Biology AP

Gene

a segment of DNA that is located in a chromosome and that codes for a specific hereditary trait

What is a monomer?

a smaller molecule that serves as the building blocks of polymers.

isotonic

a solution having the same concentration of solute

hypertonic

a solution with a higher concentration of solute

hypotonic

a solution with a lower concentration of solute

Sex-Linked Trait

a trait that is determined by a gene found on one of the sex chromosomes, such as the X chromosome or the Y chromosome in humans

Cancer

a tumor in which the cells begin dividing at an uncontrolled rate and become invasive

What does the structure of DNA look like?

a twisted ladder

Name the 4 nitrogen bases

adenine, thymine, guanine, cytosine

Life Cycle

all of the events in the growth and development of an organism until the organism reaches sexual maturit

What is the main importane of pump in maintaining membrane potential

an indirect one of maintaing ion concetnration gradeints for K and Na

haploid organism

an organism that has only a single copy of its genome in each of its cells; possesses no homologous chromosomes.

On the figure with question 22, label the ester linkages. -look at diagram from question 22

answer on diagram from question 22

What nucleotide component contain nitrogen?

base

Which part of the cell acts an the insultaor part of a capacitor?

bilayer of the cell membrane ion channels through the membrane make the cell membrane a leaky capacitor. changing the amount of charge stored on either side of the membrane changes the membrane potential

receptor-mediated endocytosis

bulk transport of substances into the cell where the molecules must first bind to specific receptors in the plasma membrane

Name two saturated fats.

butter and most animal fats

What equation do you use for diffusion potential when the membrane is permeable to several different ions?

by using the above equation, you can figure out how a change in ion concentration or ion permeability can change the membrane potential.

What is the role of cAMP?

cAMP activates protein kinase A, which causes a cellular response.

Here are the three hexose sugars. Label each of them. Notice that all sugars have the same two functional groups. Name them: -Diagram in question 10 C=O __________________ -OH __________________

carbonyl group hydroxyl group

Name the correct carbohydrate for each? Structural polysaccharide that comprises plant cell walls

cellulose

Distinguish between channel proteins and carrier proteins

channel - passively transports molecules across membrane by creating a selective tunnel carrier proteins - actively or passively transports molecules through conformational changes

Name the correct carbohydrate for each? Structural polysaccharide that gives cockroaches their crunch

chitin

What is countertransport?

coupled transport where the inward movement of a substance drives the outward movement of another substance

Define peptide bond

covalent bond in which 2 amino acids are joined by a dehydration reaction

THe sides of the ladder are made up of alternating what?

deoxyribose and phosphate molecules

What kind of sugar is found in a nucleotide?

deoxyribose sugar

Haploid

describes a cell, nucleus, or organism that has only one set of unpaired chromosomes

Homozygous

describes and individual that has identical alleles for a trait on both homologous chromosomes

True-breeding

describes organsims of genotypes that are homozygous for a specific trait and thus always have the same phenotype for that trait

exocytosis

discharge of material from vesicles

pinocytosis

endocytosis of a liquid

phagocytosis

endocytosis of a particulate

What is facilitated diffusion? Is it active or passive? Cite two examples.

facilitated = diffusion mediated by membrane proteins; passive transport Two examples: - movement of ions through a protein channel - movement of amino acids through a carrier protein

Name the correct carbohydrate for each? Two monomers of this form maltose

glucose

Name the correct carbohydrate for each? Is a storage polysaccharide produced by vertebrates; stored in your liver

glycogen

Distinguish between glycolipids and glycoproteins

glycoproteins - proteins/carbohydrate chain characteristic of an individual (ie MHC - helps recognize the individual) glycolipids - lipid/carbohydrate chain shape characteristic of tissue

Membrane carbohydrates are important in cell-cell recognition. What are two examples of this?

glycoproteins = major histocompatibility complex glycolipid = A B O blood group marker

What base attaches to cytosine?

guanine

Substrate

The reactant on which an enzyme works.

Why are the strands said to be antiparallel?

The strands are said to be antiparallel because they run in opposite 5' -> 3' directions from each other.

Enzyme-substrate complex

The substrate is temporarily bound to its enzyme

Reception

The target cells detection of a signal coming from outside the cell a chemical signal is detected when it binds to a cellular protein

Response

The transduced signal finally triggers a specific cellular response

Found within the nucleus are the chromosomes which are made of chromatin. What are the two components of chromatin? When do the thin chromatin fibers condense to become distinct chromosomes?

The two components of chromatin are DNA and Protiens. When thin chromatin fibers coil up (condense), be coming thick enough to be distinguished as seperate structures.

binary fission

The type of cell division by which prokaryotes reproduce. Each dividing daughter cell receives a copy of the single parental chromosome.

In the 1960s, the Davson-Danieli model of membrane structure was widely accepted. Describe this model and then cite two lines of evidence that were inconsistent with it.

There is a phospholipid bilayer between 2 levels of proteins. The problems were: the model assumed all membranes are identical and also protein placement was illogical.

Explain what is meant when we say a molecule is amphipathic.

There is both a hydrophobic and hydrophilic region.

What are transcription factors?

They are molecule complexes that control which genes are turned on and transcribed to mRNA

What are peripheral proteins?

They are not embedded. They are appendages.

What is the sodium-potassium pump? (Fig 7.18)

This transport system pumps ions against steep concentration gradients: Sodium ion concentration [Na+] is high outside the cell and low inside, while potassium ion concentration [K+] is low outside the cell and high inside. The pump oscillates between two shapes in a cycle that moves 3 Na+ out of the cell for every 2 K+ pumped into the cell. The two shapes have different affinities for Na+ and K+. ATP powers the shape change by transferring a phosphate group to the transport protein (phosphorylating the protein).

Response

Transduced signal triggers some sort of cellular response.

What is the role of protein kinase?

Transfer phosphate groups from ATP to proteins.

What types of microscopes support the fluid-mosaic model of the cell membrane

Transmission Electron Microscope and Scanning Electron microscopes

Electrogenic Pump

Transports protein that generates voltage across a membrane.

Each activated protein in tyrosine kinase triggers a signal ______ pathway leading to a ______ response.

Transuction... cellular

What is an electrical capacitor?

Two pieces of conducting material separated from each other by an insulating materail. The capacitor stores charges of opposite sign on the facing surfaces.

eukaryotic asexual division

Type of division where 2 new cells develop from a single cell--> mitosis

Draw a fatty acid chain that is eight carbons long and is unsaturated. Circle the element in your chain that makes it unsaturated, and explain what this means. (diagram from question 25)

Unsaturated fatty acids have one or more double bond, with one fewer hydrogen atom on each double bonded carbon from the carbon skeleton. This means they are liquid at room temperature.

Describe ENa+, EK+, Vm relative to each other.

Vm is membrane potential. Value is between the Ena and Ek actual membrane potential of cell is balance between Ek which changes if K concentration change and Ena. At rest the cell is much more permeable to K than to Na so the membrane potential is closer to Ek. During an action potential the permeability of the membrane to Na increasing and the membrane potential moves closer to Ena

Membrane Potential

Voltage across a membrane

What is membrane potential? Which side of the membrane is positive?

Voltage across the membrane. Outside is positive.

What is the water potential equation?

Water potential = Water potential P + Water potential S

What is the equation in finding out Water solute potential?

Water solute potential = iRCT

Describe how the membrane has been modeled as an electrical circuit.

When discussing the electrical circuit model we use the term conductance of an ion rather than permeability of the membrane to an ion.

Plasmolysis

When plants are in a hypertonic environment and they wilt.

What is the role of DNA helices in the replication of DNA?

helices breaks the hydrogen bonds between nucleotides, separating the double helix

What is the ionization constant for C6H12O6

i=1

Chromosome

in a eukaryotic cell, one of the structures in the nucleus that are madeup of DNA and protein; in a prokaryotic cell, the main ring of DNA

mitosis

in eukaryotic cells, a process of cell division that forms two new nuclei, each of which has the same number of chromosomes

Mitosis

in eukaryotic cells, a process of cell division that forms two nuclei, each of which has the same number of chromosomes

What were the ideas concerning the plasma membrane models of Gorter and Grendel?

- Cell membrane was a phospholipid bilayer

Type of Protein: Motor and Contractile Proteins -what is the function? -give an example

- Movement -actin and myosin

What were the ideas concerning the plasma membrane models of Davson and Danielli?

- Sandwich Model - Phospholipid bilayer coated on both sides by hydrophilic proteins

What does selective permeability mean and why is that important to cells?

- Some substance can pass through more easily than others - Cell can seal itself off from environment but still take in nutrients and eliminate wastes

Here is a figure that shows the structure of a phospholipid. Label the sketch to show the phosphate group, the glycerol, and the fatty acid chains. Also indicate the region that is hydrophobic and the region that is hydrophilic. -Look for diagram from question 31

- answers are on diagram from question 31 -tail is hydrophobic -head is hydrophilic

Enzymes are an important type of protein. They will be studied in Chapter 8. For now, use this sketch to review what you know about enzymes. Label the active site, the substrate, and the products. Show what happens to water. -Look at diagram from question 39 -Is this reaction dehydration synthesis or hydrolysis?

- answers found on diagram from question 39 -dehydration synthesis

To summarize, a phospholipid has a glycerol attached to a phosphate group and two fatty acid chains. The head is hydrophilic, and the tail is hydrophobic. Now, sketch the phospholipid bilayer structure of a plasma membrane. Label the hydrophilc heads, hydrophobic tails, and location of water.

- answers is found in question 34 -water is found on the outside -hydrophilic heads are on the outside -hydrophobic tails are found on the inside

Why is membrane sidedness an important concept in cell biology?

- the two lipid layers have different lipid layers have different lipid composition. Each protein has a directional orientation. - molecules that start on the inside of the ER end up on the outside of the plasma membrane

-What 2 monosaccharides form maltose? -Where is maltose found?

-2 glucose molecules -malt sugar

What is diffusion and how does a concentration gradient relate to passive transport?

-Diffusion- movement of molecules that spread out in a space. -Diffusion across a semi permeable membrane is passive transport -Substances diffuse down their concentration gradient without using energy.

Monomers are connected in what type of reaction? What occurs in this reaction?

-Monomers are connected in a dehydration reaction or condensation reaction -During a dehydration reaction, two monomer molecules are covalently bonded to each other, with the loss of a water molecule. In this reaction, each monomer contributes part of the water molecule that is released during the reaction. This reaction is repeated as monomers are added to the chain one by one, making a polymer.

What is deoxyribose?

-Pentose sugar found in DNA nucleotides

What is ribose?

-Pentose sugar found in RNA nucleotides

Type of Protein: Receptor Protein -what is the function? -give an example

-Response of cell to chemical stimuli -G protein-coupled receptors; tyrosine kinase receptors

What is RNA?

-Ribonucleic acid -a copy of DNA that has a phosphate group/phosphoric acid, a ribose sugar and nitrogen containing bases (adenine, uracil, guanine, cytosine)

Ratios of different types of lipids?

-Some types of phospholipids make the membrane more fluid than others -Cells can alter the rations quickly -Different organelles have diff. ratios of lipids

Type of Protein: Storage -what is the function? -give an example

-Storage of amino acids -Casein, which is the major source of amino acids for baby mammals; ovalbumin, the protein of egg white

List the 6 broad functions of membrane proteins.

-Transport - Enzymatic activity - Signal Transduction - Cell-Cell recognition -Intercellular Joining - Attachment to cytoskeleton and ECM

Type of Protein: Transport Protein -what is the function? -give an example

-Transport -Proteins embedded in the plasma membranes; aquaporins; hemoglobin

Level of Protein Structure: Quaternary (IV^0) -explanation -example

-aggregation of 2 or more polypeptide subunits -ex. hemoglobin, collagen

Level of Protein Structure: Primary (I^0) -explanation -example

-amino acids linked with a unique sequence -ex. transthyretin

The monomers of proteins are amino acids. Sketch an amino acid here. Label the alpha or central carbon, amino group, carboxyl group, and R group. -know the actual atom arrangement

-answer found in question 41

What are the building blocks of fats? Label them on this figure. -look at the diagram in question 22

-answers are on diagram from question 22

The components of a nucleic acid are a sugar, a nitrogenous base, and a phosphate group. Label each on the figure below. Also label the end of the strand on the left side of the figure below that has the number 5 sugar 5' and the other end of the chain 3'. -look at diagram from question 53

-answers on diagram from question 53

Know how to identify a dipeptide, polypeptide, and peptide bond -diagram on question 44

-answers on question 44

What does messager RNA do?

-mRNA is produced in the nucleus by transcription using DNA as a template -contains bases complimentary to DNA -Carries DNA's message out of the nucleus to the ribosomes in the cytoplasm

Notice that two monomers are joined to make a polymer. Since the monomers are monosaccharides, the polymer is a disaccharide. Three disaccharides have the formula C12H22O11. What are the 3 disaccaride?

-maltose -sucrose -lactose

What is adenine, guanine, cytosine, uracil and thymine?

-nitrogen containing bases that pair together in RNA and DNA

What is a phosphate?

-part of nucleotide backbone in DNA and RNA

What are nitrogenous bases?

-part of nucleotides in DNA and RNA

What is a sugar-phosphate backbone?

-part of nucleotides in DNA and RNA

What does Ribosomal RNA do?

-rRNA is a component of ribosomes -helps in protein synthesis by decoding mRNA into amino acids

What is represented by R? How many are there?

-side chains of amino acids -there are 20

There are two categories of polysaccharides. Name them and give examples.

-storage (ex. glycogen, starch) -structural (ex. cellulose, chitin)

What does Transfer RNA do?

-tRNA delivers individual amino acids to the ribosomes during protein synthesis

What is the process of DNA replication (step by step)?

1) Helicase unzips the DNA 2) DNA polymerase adds new nucleotides in the correct order 3) Cement backbone 4) DNA is rezipped by the ligase

Chaperone proteins or chaperonins assist in the proper folding of proteins. Annotate this figure to explain the process. -Look at diagram from question 50 to see the steps

1. An unfolded polypeptide enters the cylinder from one end. 2. The cap attaches, causing the cylinder to change shape in such a way that it creates a hydrophilic environment for the folding of the polypeptide. 3. The cap comes off, and the properly folded protein is released.

Fig 7.18 - Describe the steps that occur in the operation of the sodium-potassium pump, which is an example of active transport.

1. Cytoplasmic Na+ binds to the sodium-potassium pump. The affinity for Na+ is high when the protein has this shape. 2. Na+ binding stimulates phosphorylation (the transfer of a phosphate group to the transport protein) by ATP. 3. Phosphorylation leads to a change in protein shape, reducing its affinity for Na+, which is released outside. 4. The new shape has a high affinity for K+, which binds on the extracellular side and triggers release of the phosphate group. 5. Loss of the phosphate group restores the protein's original shape, which has a lower affinity for K+. 6. K+ is released; affinity for Na+ is high again, and the cycle repeats.

What are the 3 different functions of RNA?

1. Messanger RNA (mRNA) 2. Ribosomal RNA (rRNA) 3. Transfer RNA (tRNA)

Endomembrane system function to digest a cellular component.

1. Nuclear envelope is connected to rough ER, which is also continuous with smooth ER. 2. Membrane and proteins produced by the ER flow in the in the form of transport vesicles to the Goligi. 3. Golgi pinches off transport vesicles and other vesicles that give rise to lysosomes, other types of specialized vesicles, and vacuoles. 4. Lysosome is available for fusion with another vesicle for digestion. 5. Transport vesicle carries proteins to plasma membrane for secretion. 6. Plasma membrane expands by fusion of vesicles; proteins are secreted from cell.

Three functions/ materials of Central vacuoles.

1. Proteins stockpiles in vacuoles of storage cells in seeds. 2. Main repository of inorganic ions, such as potassium and chloride. 1. Disposal sites for metabolic by-products.

What are the three major factors that affect membrane fluidity?

1. Ratios of different types of lipids 2. Saturated vs. Unsaturated phospholipids 3. Amount of cholesterol

What is the function of the proteins in the cell membrane

1. Support 2. Transport through the membranes 3. Communication & cell identification

List and describe three major functions of the smooth ER.

1. Synthesis of lipids, oils, phospholipids, and steroids. 2. Other enzymes of smooth ER help detoxify drugs and poisons. 3. Metabolism of carbohydrates.

What are the 3 types of transmembrane proteins

1. carriers - actively or passively transport molecules across membranes 2. Channel proteins - passively transport molecules across membrane 3. Receptor proteins - transmit information into the cell

Purposes of cell division

1. reproduction of entire uni-cellular organism 2. Growth of multicellular organism (egg+sperm=gamete--> adult) 3. repair and replacement of cells 4. sperm and egg production (gamete)

How many hydrogen bonds connect thymine and adenine together?

2

How many codons are needed to specify three amino acids?

3

How many hydrogen bonds connect cytosine and guanine together?

3

If a fat is composed of three fatty acids and one glycerol molecule, how many water molecules will be removed to form it? Again, what is this process called?

3 water molecule is removed (one for each fatty acid) to join the glycerol. This process is called dehydration synthesis.

In a DNA double helix, a region along one DNA strand has this sequence of nitrogenous bases: 5'-T A G G C C T-3' -Write the complementary strand. Indicate the 5' and 3' ends of the new strand.

3'-A T C C G G A-5'

A group of individuals all born at the same time is called a(n) A. cohort B. exponential population C. isopopulation D. metapopulation E. subpopulation

A

If the allele for tall (T) plants is incompletely dominant over the allele for short (t) plants, the offspring resulting from a cross between two Tt plants will likely be A. 1/4 tall, 1/2 intermediate height, 1/4 short B. 1/2 tall, 1/4 intermediate height, 1/4 short C. 1/4 tall, 1/4 intermediate height, 1/2 short D. all tall E. all intermediate height

A

If two organisms use the same resources and those resources are insufficient to supply their combat needs, the organisms' interactions constitute A. competition B. predator-prey C. mutualism D. commensalism E. amensalism

A

In Yellowstone National Park, elk population densities have been controlled using A. wolves B. decomposers C. leaves D. mountain lions E. grass

A

In Yellowstone National Park, removal of wolves caused ripple effects across trophic levels result in A. a trophic cascade B. succession C. ecological transition D. gross primary productivity E. net primary productivity

A

In a biological membrane, the phospholipids are arranged with the fatty acid chains facing the interior of the membrane. As a result, the interior of the membrane is A. hydrophobic B. hydrophilic C. charged D. polar E. filled with water

A

In the Galapagos archipelago, small ground finches can eat flower nectar or seeds. Finches eating flower nectar compete with carpenter bees. On an island where bees and finches compete, what would happen to the finches if the bees went extinct due to disease? A. Smaller birds eating nectar would increase in frequency over time. B. All of the birds would decrease in size and only eat nectar. C. The size of the birds would stay the same. D. All of the birds would increase in size and eat only seeds. E. The birds would likely go extinct without the bees.

A

Mendel concluded that each pea has two units for each character, and each gamete contains one unit. Mendel's "unit" is now referred to as a(n) A. gene B. character C. locus D. transcription factor E. None of the above

A

The hydrogen ion gradient is maintained by A. electron transport and proton pumping B. the splitting of water C. the ionization of glucose D. ATP synthase E. acetyl CoA

A

Viruses A. can mutate B. can extract energy from their environment C. have a cell membrane D. can reproduce on their own E. are made of cells

A

Which of the following interactions between atoms is the strongest? A. covalent bonds B. van der Waals interactions C. hydrogen bonds D. ionic bonds E. hydrophobic interactions

A

Which of the following is an example of passive transport? A. facilitated diffusion B. sodium-potassium pump C. phagocytosis D. exocytosis E. pinocytosis

A

Which of the following processes does not involve the uptake of materials into the cell? A. exocytosis B. pinocytosis C. endocytosis D. receptor-mediated endocytosis E. phagocytosis

A

Describe the freeze fracture technique and why is it useful in cell biology.

A cell is frozen and fractured with a knife. Fracture plane follows the hydrophobic interior, the membrane proteins go with one of he layers Allows us to see the structure of the membrane.

Catalysts

A chemical agent that increases the rate of a reaction without being consumed by the reaction.

The strands of DNA form what?

A double helix

Binary Fission

A form of asexual reprodiction in single-celled organisms by which one cell divides into two cells of the same size

Chemical Energy

A form of potential energy that is available for release in chemical reactions

Activation Energy

A free energy of activation where the energy that must be absorbed by reactants to reach the unstable transition state, in which bonds are likely to break, and form which the reaction can proceed

What is a ligand? What do ligands have to do with receptor-mediated endocytosis?

A ligand is a molecule that binds to a receptor. Ligands mediate receptor-mediate endocytosis.

What happens in Tay-Sachs Disease? Explain the role of lysosome.

A lipid digesting enzyme is missing or inactive, and the brain becomes impaired by an accumulation of lipids in the cells.

What is a lysosome? What do they contain? What is their pH?

A lysosome is a membranous sac of hydrolytic enzymes that animal cell uses to digest macromolecules. Contains lysosomal enzymes.

Feedback Inhibition

A metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway.

What is ligand?

A molecule that binds specifically to the receptor sites of another molecule

What is an amphipathic molecule?

A molecule that has a hydrophilic and hydrophobic end. Example: phospholipids

Describe the fluid-mosaic model of membrane structure by Singer and Nicolson

A mosaic of proteins float in or on a fluid lipid bilayer

Synaptic Signaling

A nerve cell releases neurotransmitter molecules into a synapse, stimulating the target cell.

G-protein-linked receptor

A plasma membrane receptor that works with the help of a G-protein

Active Site

A pocket groove on the surface of the protein where catalysis occurs

Tyrosine kinase receptor

A receptor protein in the plasma membrane that responds to the binding of a signal molecule by catalyzing the transfer of phosphate groups from ATP to tyrosines on the cytoplasmic side of the receptor. The phosphorylated tyrosines activate other signal-transduction proteins within the cell.

Scaffolding protein

A scaffolding protein is a large relay protein to which several other relay proteins are attached. This facilitates signal transduction pathways because it gathers together all of the proteins involved in the pathway, thus enhancing speed and accuracy of signal transfer.

gene

A segment of DNA on a chromosome that codes for a specific trait

Ligand

A signal molecule, a molecule that binds specifically to another molecule, usually a larger one

Describe why many neurons and intestinal cells each have greatly increased surface area.

A sufficiently high ratio of surface area to volume is especially important in cells that exchange a lot of material with their surroundings.

What is a trans fat? Why should you limit them in your diet?

A trans fat is an unsaturated fat with a trans double bond; the result of the process of hydrogenating vegetable oils to prevent lipids from separating out in liquid (oil) form. Trans fats should be limited in your diet because they have been found to contribute to atherosclerosis, a cardiovascular disease caused by plaque buildup within the walls of blood vessels.

Oxygen gas (O₂) in Earth's early atmosphere A. allowed organisms to move from sea to land B. was not toxic to most prokaryotes C. allowed the evolution of anoxic metabolism D. increased damage to organisms by allowing more ultraviolet light in E. depleted ozone in the atmosphere

A.

Consider the following reaction: C6H12O6 + C6H12O6 C12H22O11 A. The equation is not balanced; it is missing a molecule of water. Write it in on the correct side of the equation. B. Polymers are assembled and broken down in two types of reactions: dehydration synthesis and hydrolysis. Which kind of reaction is this? C. Is C6H12O6 (glucose) a monomer, or a polymer? D. To summarize, when two monomers are joined, a molecule of __________ is always removed.

A. C6H12O6 + C6H12O6 C12H22O11 + H2O B. Dehydration synthesis C. Monomer D. water

endocytosis

infolding of the plasma membrane allowing for bulk transport of substances into a cell

What is cotransport? Explain how its understanding is used in our treatment of diarrhea.

ATP is used to indirectly provide transport for certain molecules. On molecule is expelled via ATP, and then it returns to the cytoplasm via a cotransporter in addition to a different molecule, that would not be able to do so without the first molecule. It is useful in sugar and sulfate mixes when suffering from diarrhea.

How is ATP specifically used in active transport?

ATP transfers a phosphate group to a transport protein, this powers the change in shape to move the substances against their concentration gradient.

Describe active transport. What type of transport proteins are involved, and what is the role of ATP in the process

Active transport uses energy to move materials against a concentration gradient with the use of a carrier protein or pump ATP provides the energy to power the conformation changes

Proton Pump

Actively transporting hydrogen ions. *Inside the cell is negative, therefore cations move in and anions move out*

Notice that there are five nitrogen bases. Which four are found in DNA?

Adenine, guanine, cytosine, thymine

Which four are found in RNA?

Adenine, guanine, cytosine, uracil

How do motor proteins called dyneins cause movement of cilia? How is ATP involved?

Adynein molecule persoms complex cycle of movement caused by changes in shape of the protein. ATP provieds energy.

Lipids include fats, waxes, oils, phospholipids, and steroids. What characteristic do all lipids share?

All lipids mix poorly, if at all, with water.

How does a yeast mating serve as an example of a signal transduction pathway?

Alpha yeast sends alpha signals that A yeast receives. A yeast sends A signals that only alpha can receive. The respective signals are then transduced and a response is carried out (mating).

One function of lysosomes is intracellular digestion of particles engulfed by phagocytosis. Describe this process of digestion. What human cells carry out phagocytosis?

Amoebas and many other protists eat by engulfing smaller organisms or other food particles. The food vacuole formed in this way then fuses with a lysosome, whose enzymes digest the food. Digestion products including simple sugars, amino acids, and other monomers, pass into the cytosol and become nutrients for the cell. Human cells such as macrophages (white blood cells) help defend against bacteria.

What are two benefits of multistep pathways?

Amplification of signal, and better regulation.

allele

An alternate form that a gene may have for a single trait; can be dominant or recessive

Kinase

An enzyme that catalyses the transfer of a phosphate group from ATP to another molecule

Adenylyl cyclase

An enzyme that converts ATP to cyclic AMP in response to an extracellular signal.

diploid organism

An organism that has two copies of its genome it each cell. The paired genomes are said to be homologous.

autosome

Any chromosome that is not a sex chromosome.

What is the principle of Electrical Neutrality?

Any macroscopic region of a solution must have equal numbers of positive and negative charges. So almost all the extracellular and intracellular ions are paired + with -, with just a small number of excess neg charges just inside the membrane paired with a small excess of positive charges just outside the membrane. The bulk of the cytoplasm and ECF is electroneutral. Only a small relative number of excess charge is found on either side of hte membrane.

Peter Agre received the Nobel Prize in 2003 for the discovery of aquaporins. What are they?

Aquaporins are specialized channels for water

Describe the function of enzymes in biological systems

Are biological catalysts agents that speed the rate of a reaction but are unchanged by the reaction

Enzyme

Are biological catalysts agents that speed the rate of a reaction but are unchanged by the reaction

Endergonic reaction

Are nonspontaneous; they must absorb free energy from the surroundings

Where do the nucleotides connect to each other?

At the phosphate and sugar

All the individuals of a species within a given area is known as a(n) A. deme B. population C. family D. lek E. group

B

In eukaryotes, exons are A. spliced out of the original transcript B. spliced together from the original transcript C. spliced to introns to form the final transcript D. usually much larger than introns E. larger than the original coding region

B

Which correctly illustrates the second law of thermodynamics? A. The total amount of energy in our universe todays is the same as the total amount of energy in our universe yesterday. B. As water flows through a hydroelectric dam, only some of the water's potential energy is converted to electrical energy; other energy is released as heat. C. As children grow, their bodies contain more totaly energy and a greater capacity to do work. D. Plants can transform energy from the sun into chemical energy. E. The earth has existed for billions of years because energy can be constantly reused and transformed into new ordered forms.

B

Which of the following best describes differences between eukaryotic and prokaryotic gene regulation? A. Groups of eukaryotic genes are likely to be regulated together, whereas each prokaryotic gene is usually related separately. B. Groups of prokaryotic genes are likely to be regulated together, whereas each eukaryotic gene is usually related separately. C. Bacteria have more classes of RNA polymerase than eukaryotes do. D. Prokaryotes lack global gene regulation. E. None of the above

B

Which of the following best describes natural selection? A. chance variations in traits B. the differential survival and reproduction of individuals C. the processes that lead individuals to resemble their parents D. the potential for all species to increase rapidly in number E. the immutability of species

B

Which of the following is the driving force for active transport? A. concentration gradient B. ATP hydrolysis C. ADP hydrolysis D. phosphorylation E. GTP-GDP exchange

B

Which of the following molecules is most involved in the transfer of genetic information from the nucleus to the cytoplasm? A. DNA B. mRNA C. tRNA D. proteins E. lipids

B

Which of the following organelles are found only in plants? A. endoplasmic reticulum B. glyoxysomes C. peroxisomes D. mitochondria E. Golgi

B

Which of the following processes is not dependent on interactions of plants with other organisms (including other plants)? A. obtaining nutrients B. regulating the internal environment C. competing for water D. producing fertile seeds E. dispersing seeds

B

Which of the following represents an enzyme-catalyzed reaction? A. Enzyme + Product → Enzyme + Substrate B. Enzyme + Substrate → Enzyme + Product C. Enzyme + Substrate → Product D. Enzyme + Substrate → Enzyme E. Product + Substrate → Enzyme

B

Which of the following statements about starch is false? A. Starch may be digested by people. B. The properties of starch are very similar to those of cellulose. C. Starch may be partially branched. D. Starch is a polymer of glucose. E. Starch is formed by the condensation of monomers.

B

Scientists observed that frogs with toe pads live in trees, not water. They stated "toe pads are important for life in trees." This statement is an example of a(n) A. experiment B. hypothesis C. prediction D. law E. theory

B.

So, as a quick review, all of the sugars in the figure above have the same chemical formula: C6H12O6. What term did you learn in Chapter 3 for compounds that have the same molecular formulas but different structural formulas?

isomers

Which two domains consists of prokaryotic cells?

Bacteria and Archaea

Why does alcohol abuse increase tolerance to other drugs such as barbiturates?

Barbiturates, alcohol, and many other drugs induce proliferation of smooth ER which are associated with detoxification enzymes, thus increasing rate of detoxification.

What molecules make up the "rungs"?

Base pairs joined by hydrogen bonding

What are pyrimidines?

Bases that have a single ring structure (thymine and cytosine)

What are purines ?

Bases the have a double ring structure (adenine and guanine)

Why is DNA replication considered "semi-conservative"

Because each new double helix contains 1 old and 1 new strand. The mother strand serves as a template for a new strand. The two strands are complementary but not identical

As the external concentration of K decreases, what happens to the Nernst Potnetial of K?

Becomes more negative and the membrane potential becomes more negative.

What is the difference between phagocytosis and pinocytosis.

Both are forms of endocytosis (uptake of bulk material by the formation of a vesicle through the plasma membrane). Phagocytosis is "cell eating" (solid object) and pinocytosis is "cell drinking" (extracellular fluid).

The formation of ethanol from pyruvate is an example of A. an exergonic reaction B. an extra source of energy as the result of glycolysis C. a fermentation process that takes place in the absence of oxygen D. cellular respiration E. None of the above

C

The mitotic spindle is composed of A. chromosomes B. chromatids C. microtubules D. chromatin E. centrosomes

C

Which of the following molecular structures is incorrect? A. CH₃-CH₃ B. CH₃-NH₃+ C. CH₃-NH₃ D. CH₂==CH₂ E. CH₃-NH₂

C

Which of the following structures is directly involved with the movement of organelles within a cell? A. endoplasmic reticulum B. mitochondrion C. microtubules D. intermediate filaments E. Golgi apparatus

C

White eyes is a recessive sex-linked trait in fruit flies. If a white-eyed female fruit fly is mated to a red-eyed male, their offspring should be A. 50 percent red-eyed and 50 percent white-eyed for both sexes B. all white-eyed for both sexes C. all white-eyed males and all red-eyed females D. all white-eyed females and all red-eyed males E. 50 percent red-eyed males, 50 percent white-eyed males, and all red-eyed females

C

You are an ecologist investigating fruit-eating in a species of monkey. You find that some monkeys regularly climb to the tops of trees in search of fruit while other monkeys forage low in trees or on the ground for fruit. If fruits are not as abundant low in trees or on the ground, you would expect the non-climbing monkeys to have _________ in population. A. no difference in fitness or frequency B. higher fitness and a decrease in frequency C. lower fitness and a decrease in frequency D. lower fitness but no change in frequency E. lower fitness and an increase in frequency

C

Oceans were a good environment for early organisms because they A. contained ozone B. were rich in oxygen C. shielded organisms from ultraviolet light D. obviated the need for a cell membrane E. shielded organisms from visible light

C.

Relationships between living organisms can best be gleaned by comparing their A. anatomical features B. metabolic processes C. genomes D. fossil records E. behavior

C.

Most monosaccharides are some multiple of (CH2O). For example, ribose is a 5-carbon sugar with the formula C5H10O5. It is a pentose sugar. (From the root penta-, meaning five.) What is the formula of a hexose sugar?

C6H12O6

How does CO2, Glucose, H+, O2, and H2O cross the membrane?

CO2 through diffusion, Glucose through carrier proteins, H+ through protein channels, O2 through diffusion, H2O through diffusion and aquaporins.

Potential Energy

Capacity of matter to cause change as a consequence of its location or arrangement.

The large molecules of all living things fall into just four main classes. Name them.

Carbohydrates, Lipids, Proteins, Nucleic Acids

Uniporter

Carrier proteins that transport only one particular molecule.

Antiporter

Carrier proteins that transport two molecules in opposite directions.

Symporter

Carrier proteins that transport two molecules in the same direction

What does a kinase enzyme do?

Catalyzes transfer of phosphate groups.

Pinocytosis

Cell drinking, droplets are engulfed into a vesicle

Distinguish between channel proteins and carrier proteins.

Channel proteins do not change, the just provide a channel. Carrier proteins change shape and hold onto passengers as they change shape.

What are aquaporins?

Channel proteins for water.

What are the two forces that drive the diffusion of ions across the membrane? What is the combination of these forces called?

Chemical force, and electrical force. These forces are called electrochemical forces.

Some people refer to this structure as three hexagons and a doghouse. What is it? -look at diagram from question 36

Cholesterol (a steroid)

What rule is used to join the free nucleotides to the exposed bases of the DNA?

Complementary base rule

Organization of microtubules

Composed of nine sets of triplet microtubules

Describe the importance of calcium?

Concentration of free ionized Ca++ in the cytoplasm is kept very low. Most intracellular calcium is sequestered in the smooth endoplasmic reticulum and thus does not directly affect ECa++ The equilibrium potential of Ca++ varies but is always a large positive number. The membrane is usually impermeable to Ca++

ATP (adenosine triphosphate)

Consists of nitrogenous base adenine bonded to the sugar ribose, which is connected to a chain of three phosphate groups.

Photosynthesis is the process that uses light energy to extract hydrogen atoms from glucose A. glucose B. chlorophyll C. CO₂ D. water E. None of the above

D

Which of the following organelles is involved in energy conversions? A. peroxisomes B. vacuoles C. lysosomes D. chloroplasts E. nuclei

D

Which of the following proteins powers the movement of both cilia and vesicles within a cell? A. myosin B. keratin C. actin D. dynein E. kinesin

D

Which of the following statements about condensation reactions is false? A. Protein synthesis results from them. B. Polysaccharide synthesis results from them. C. They involve covalent bonds. D. They consume water as a reactant. E. Different condensation reactions produce different kinds of macromolecules.

D

Which of the following statements about plant cytokinesis is true? A. It begins when telophase ends. B. A division furrow completely separates the cytoplasm. C. It is under the control of Ca2+. D. Vesicles fuse to form a cell plate. E. The spindle fibers break down to form a cell plate.

D

Which statements about the trp operon is false? A. The presence of tryptophan in the medium inhibits the expression of the structural genes of the trp operon. B. RNA polymerase binds to the trp promoter when tryptophan is absent from the medium. C. Repression of gene expression can save the cell energy. D. Tryptophan controls the expression of the genes for the enzymes of the tryptophan synthesis pathway by binding directly to the trp operator. E. The trp operon contains a promoter and an operon.

D

Which of the following represents a scientific point of view? A. The positions of the sun, moon, and stars provide guidance for making decisions. B. Inner strength comes from beauty in nature. C. Earth was created by divine forces. D. Comparing the genomes of organisms allows us to create phylogenetic trees. E. Meditation helps to solve problems.

D.

What specifically happens to a cell during the process of apoptosis?

DNA chopped up, cell shrinks, lobes up, vesicles form, digestion by scavenger cells.

How do ribose and deoxyribose sugars differ?

Deoxyribose sugar lacks an oxygen atom on the second carbon in the ring

What is the difference between an aldehyde sugar and a ketone sugar?

Depending on the location of the carbonyl group, a sugar is either an aldose (aldehyde sugar) or a ketose (ketone sugar). Glucose, for example, is an aldose; fructose, an isomer of glucose, is a ketose. In aldehyde sugars, the carbonyl group is at the end of the carbon skeleton, while in the ketone sugars, the carbonyl group is within the carbon skeleton.

Why is facilitated diffusion considered passive transport?

Despite the help of transport proteins, facilitated diffusion is considered passive transport because the solute is moving down its concentration gradient, a process that requires no energy. Facilitated diffusion speeds transport of a solute by providing efficient passage through the membrane, but it does not alter the direction of transport. Some transport proteins, however, can move solutes against their concentration gradients, across the membrane from the side where they are less concentrated (whether inside or outside) to the side where they are more concentrated.

Reception

Detection of signaling molecule

Describe 3 types of Passive Transport

Diffusion Osmosis Facilitated Diffusion

Passive transport

Diffusion across a biological membrane that does not require energy.

Osmosis

Diffusion of water over a semipermeable membrane.

Here is a model of DNA, which was proposed by James Watson and Francis Crick. What is this shape called?

Double helix

A second function of lysosomes is to recycle cellular components in a process called autophagy. Describe this process.

During autophagy, a damaged organelle or small amount of cytosol becomes surrounded by a double membrane, which is of origin unknown and a lysosome fused with the membrane of the vesicle.

A builder is planning to develop a parcel of land. THe local zoning regulations require that the builder set aside some of the parcel's open space as wildlife habitat. The builder can either set aside one large parcel or multiple, smaller plots. Which would be considered the best choice from the point of view of a conservation biologist? A. The smaller plots are the least acceptable option. B. There is no difference between the two options. C. The larger plot is the only acceptable option. D. The larger plot is the least acceptable option. E. Smaller plots are acceptable if they have corridors connecting them.

E

An element that contains ten protons and ten electrons is likely to A. be radioactive B. form ionic bonds with another element C. be toxic D. form covalent bonds with another element E. be chemically inert (stable)

E

An invasive plant species from Asia appears in your yard and you decide to introduce a beetle from Asia that eats that plant species. What is the likely outcome of this decision? A. The beetles will eat all of the invasive plants and then all of the beetles will die due of starvation. B. The beetles will eat all of the invasive plants and then switch to eating a native plant. C. The beetles will not eat any plants, native or invasive. D. The beetles will ignore the invasive plants and eat only native plants. E. There is no way to predict the outcome; any of the above could occur.

E

Carrying capacity (K) is determined by A. availability of resources B. diseases C. predators D. social interactions E. All of the above.

E

Which of the following organelles contains DNA? A. nucleus B. chloroplast C. mitochondria D. ribosome E. A, B, and C

E

Which of the following statements about ATP is true? A. It is an energy-storage compound. B. It is the cell's principle compound for energy transfers. C. It stands for adenosine triphosphate. D. It is the molecule all living cells rely on to do chemical work. E. All of the above

E

Genomes are A. only found in animal and plant cells B. made of proteins C. usually made of RNA D. the shared genetic, information among all living cells E. the sum of genetic information in a cell

E.

Here is the abbreviated ring structure of glucose. Where are all the carbons? -diagram in question 13

Each corner represents a carbon; each carbon in this figure is labeled 1 through 6.

Synaptic signaling

Electrical signals trigger chemical signal. Very specific; affects only target cell. Examples are neurotransmitters.

List all the structures of the endomembrane system.

Endoplasmic Reticulum (smooth and rough), Lysosomes, Golgi Apparatus, Vacuoles.

primary active transport

Energy from hydrolysis of ATP causes shape change in transport protein so that bound solutes (ions) are "pumped" across the membrane

List four important functions of fats.

Energy storage, long-term food reserve in mammals, adipose tissue cushions vital organs, body insulation.

Phagocytosis

Engulfs solid particles, packaged in vesicles, fuses with a lysosome and digests particles

How do scaffolding proteins enhance a cellular response?

Enhancement of speed and accuracy because the rate of response is no longer limited by rate of diffusion.

What is the relationship between ion channels and gated channels and facilitated diffusion?

Facilitated diffusion allows polar molecules and ions to passively diffuse through the membrane channel proteins such as ion channels which function as gated channels allows water or specific solutes to passively diffuse.

What is facilitated diffusion? Is it active or passive? Cite two examples.

Facilitated diffusion is diffusion along transport proteins. It is passive. Examples are aquaporins and neurotransmitters.

Turgid

Firm.

What is the difference between a first messenger and a second messenger?

First messenger is the ligand, second messenger is any small, non-protein components of a signal transduction pathway.

Vacuoles Food vacuoles Contractile Vacuoles Central vacuoles

Food- formed by phagocytosis Contractile- many freshwater protists pump excess water out of the cell, thereby maintaining a suitable concentration of ions and molecules inside the cell. Central- In plants hydrolysis is carried out in vacuoles. Develops by the coalescence of smaller vacuoles, themselves derived from Golgi Apparatus and Endoplasmic Reticulum.

secondary active transport

Form of active transport which does not use ATP as an energy source; rather, transport is coupled to ion diffusion down a concentration gradient established by primary active transport.

Four functions of microfilaments. Actin- globular protein

Form structural networks Bear tension Help support cell shape Gives outer cytoplasmic layer of a cell

Why is the inner membrane of mitochondria highly folded?

Give the mitochondrial membrane a larger surface area, thus enhancing productivity of cellular respiration.

What is the difference between glycolipids and glycoproteins.

Glycolipids are carbohydrates covalently bound to lipids. In glycoproteins, carbohydrates are covalently bound to proteins

What are two examples of membrane carbohydrates that are important in cell-cell recognition?

Glycolopids, and glycoproteins

What is membrane potential?

Gradient of electrical potential energy across a cell membrane.

How does a hormone qualify as a long-distance signaling example?

Hormones can travel to any part of the body via the circulatory system.

Why can you not digest cellulose? What organisms can?

Humans cannot digest cellulose because they lack the enzyme that can hydrolyze its beta linkages. Humans do posses enzymes that digest starch by hydrolyzing its alpha linkages; however, these enzymes cannot hydrolyze the beta linkages of cellulose because of the distinctly different shapes of these two molecules. Some microbes can digest cellulose into glucose monomers with cellulose enzymes. Many eukaryotic herbivores (cow to termites) have relationships with microbes therefore they can digest cellulose. Also some fungi

Transport proteins

Hydrophilic channel for faster transport.

Sodium-potassium pumps help nerve cells establish a voltage across their plasma membranes. Do these use ATP or produce ATP? Explain.

I believe these pumps use ATP in a process called phosphorylation (where a phosphate that is broken off from the ATP molecule is used by the pump in order to change its confirmation and allow for transport of hydrogen ions across the membrane, from the cytoplasmic fluid to the extracellular fluid.) The pump uses ATP. To establish a voltage, ions have to be pumped against their gradients, which requires energy.

Cell-cell recognition proteins

Identification between cells.

Name the correct carbohydrate for each? "Milk sugar"

lactose

What is a major disadvantage of an electron microscope?

In the process of preparing the specimen, the cells are killed.

What is special about intracellular receptors?

Intracellular receptors are typically proteins dissolved in the cytosol or nucleus of a target cell. They may become activated with the binding of a signal molecule. The activated form may then respond or cause a change.

Explain why an investment of activation energy is necessary to initiate a spontaneous (exergonic) reaction.

Investment of activation energy is known as a free energy of activation where the energy that must be absorbed by reactants to reach the unstable transition state, in which bonds are likely to break, and form which the reaction can proceed

How does cholesterol affect membrane fluidity?

It acts as a fluid buffer. It makes it more fluid in very cold temperatures, by not allowing the membrane to come in too close. In too warm temperatures it decreases fluidity.

How does tyrosine kinase function in the membrane receptor?

It allows for the activation of many signal transduction pathways.

How does decreasing temperature affect membrane fluidity.

It decreases fluidity.

What affect do phospholipids with unsaturated hydrocarbon chains have on the membrane fluidity?

It increases fluidity because of more kinks.

What happens to the cytoplasmic concentration of calcium when it is used as a second messenger?

It increases.

How does cholesterol have the ability to both increase and decrease membrane fluidity?

It inserts itself in between the fatty acid tails of the bilayer. - At high concentrations, cholesterol blocks phospholipids from moving laterally (decreases fluidity) - At low concentrations, prevents phospholipid tails from packing in tightly (increases fluidity)

What happens to cell's K potential when the ECF con is rasied?

It is decreased bc they are almost equal.

Describe the role of Na/K pump?s

It is electrogenic every cycle the cell loses 1 pos charge and thus becomes more neg inside how muc the pump contributes directly to membrane potential varies among differnt tissues.

A G protein is also a GTPase enzyme. Why is this important?

It stops the signal and converts GTP back to GDP

Intercellular joining

Join different cells together.

How do yeast cells communicate?

Yeast cells use chemical signaling to identify cells of opposite mating type and initiate the mating process. The two mating types are a and alpha

Hypotonic

Less solute relative to something.

Flaccid

Limp.

Are transport proteins specific?

Yes, an example is carrier proteins and glucose.

Explain lumen, transport vesicles, and the difference between smooth and rough ER.

Lumen- the ER membrane separates the internal compartment of the ER. Transport Vesicles- vesicles in transit from one part of the cell to another Smooth vs. Rough: Smooth- lacks ribosomes Rough- has ribosomes on surface.

What is the difference between Magnification and Resolution?

Magnification- ratio of an objects image size to its real size. Resolution- measure of the clarity of the image; it is the minimum distance two points can be seperated and still be distinguished as two points.

Attachment to cytoskeleton and ECM

Maintains cell shape and stabilize cells.

Describe the resting membrane potential. Where is the neg charge located? Where is the pos charge located? Are they balanced? What does the membrane act like?

Membrane acts as a capacitor Excess negative charge on side of membrane touching the cytoplasm Excess positive charge on side of membrane facing the extracellular fluid. Negative charge on cytoplasmic side balanced by positive charge on extracellular side

What is meant by membrane fluidity? Describe the movement seen in the fluid membrane.

Membrane is not static. It can shift and move because of unsaturated hydrocarbons. They can move by lateral movement, or by flipping.

Law of Segregation

Mendel's law that states that the pairs of homologous chromosomes seperate in meiosis so that only one chromosome from each pair is present in each gamete

Another name for centrosomes? Role of centrioles?

Microtubule- organizing center. Centrioles help organize microtubule assembly in animal cells.

Ligand

Molecule that specifically binds to another, usually bigger molecule.

Second messengers

Molecules that are involved in the signal-transduction pathway, small non-protein and water soluble

Hypertonic

More solute relative to something.

Active Transport

Movement across the cell membrane requiring energy (usually ATP) to be exerted by the cell.

Diffusion

Movement of molecules so that they spread out evenly.

Describe active transport. What type of transport proteins are involved, and what is the role of ATP in the process?

Movement of molecules through proteins, but energy is required. ATP provides energy for this. Example is the sodium potassium pump.

What hapens if the extracelluar concentration of Na is lowered, what happens to Nernst Potential of Na?

Na lowered, Nerst Potential of na decreaed an

In what body system are ligand-gated ion channels and voltage-gated ion channels of particular importance?

Nervous system

Isotonic

No net movement of water across a membrane. Amounts are equal.

What is the membrane potential of a real cell and how does it differ from a hypothetical one?

Normally the electrical forces and chemical forces on K and and are not equal and these ions are not at equilibrium. Real cells have a membrane potential which is close to but less negative than the Nernst potential of K.

How has our knowledge about cotransport proteins in animal cells helped us to find more effective treatments for diarrhea, a serious problem in developing countries?

Normally, sodium in waste is reabsorbed in the colon, maintaining, constant levels in the body, but diarrhea expels waste so rapidly that reabsorption is not possible, and sodium levels fall precipitously. To treat this life-threatening condition, patients are give a solution to drink containing high concentrations of salt (NaCI) and glucose. The solutes are taken up by the sodium-glucose cotransporters on the surface of intestinal cells and passed through the cells into the blood. This simple treatment has lowered infant mortality worldwide. (Fking amazing wow - simple knowledge - profound change in the world).

Describe the nuclear envelope. How many layers is it? What connects the layers?

Nuclear Envelope- Double membrane enclosing the nucleus; perforated by pores; continuous with ER

Give one example of signal for apoptosis coming from outside the cell, and two from inside the cell.

Out: death signaling molecule reactions with protein and activates Ced-9. IN1: Leaking form mitochondria. IN2: ER due to excessive missfolding of proteins.

What are two general types of transport? Talk about whether it uses ATP or not and talk about the concentration.

Passive Transport: No ATP High Concentration --> Low Concentration Active Transport: Uses ATP Low Concentration --> High Concentration

List three pathways often induced by calcium ions.

Pathway via mitochondria, ER, and plasma membrane.

Peripheral membrane protein

Peripheral proteins (extrinsic proteins) are present on the innermost and outermost of phospholipids bilayer. These proteins are loosely bound to the plasma membrane either directly by interactions with polar heads of phospholipids bilayer or indirectly by interactions with integral proteins. Most of the peripheral proteins are found on the innermost surface or cytoplasmic surface of the membrane.

To summarize, what are the three components of a nucleotide?

Phosphate group, sugar, nucleoside

What were the ideas concerning the plasma membrane models of Singer and Nicolson?

Phospholipid bilayer with proteins individually inserted into the bilayer with hydrophilic ends protruding.

Large molecules (polymers) are converted to monomers in what type of reaction?

Polymers are disassembled to monomers by hydrolysis, a process that is essentially the reverse of the dehydration reaction.

Exergonic Reaction

Proceeds with a net release of free energy and is spontaneous.

What is a signal transduction pathway?

Process by which a signal on a cell's surface is converted to a specific cellular response in a series of steps.

Sodium-Potassium Pump

Protein that pumps sodium and potassium across the membrane in either direction working opposite of diffusion, against the concentration gradient.

Enzymatic activity proteins

Protein's active site is exposed. Once enzyme activates, it a certain function is performed.

When cell signaling causes a response in the nucleus, what normally happens?

Proteins become transcription factors, certain genes are chosen, these are then transcribed.

The rough ER is studded with ribosomes. As proteins are synthesized, they are threaded into the lumen of the rough ER. Some of these proteins have carbohydrates attached to them in the ER to form glycoproteins. What does the ER then do with these secretory proteins?

Proteins that have carbohydrates covalently bonded to them. The carbohydrates are attached to proteins in the ER by specialized molecules built into the ER membrane.

What are integral proteins?

Proteins that penetrate the hydrophobic core.

What is a proton pump?

Proton pumps are electrogenic pumps that store energy by generating voltage (charge separation) across membranes. A proton pump translocates positive charge in the form of hydrogen ions. The voltage and H+ concentration gradient represent a dual energy source that can drive other processes, such as the uptake of nutrients. Most proton pumps are powered by ATP.

What is a key difference between receptor kinases and G protein-coupled receptors?

Receptor kinases can activate a lot more signal transduction pathways than just the one that G protein-coupled receptors can.

Concentration gradient

Region along which density of a chemical substance decreases.

When cell signaling causes a response in the cytoplasm, what normally happens?

Regulation of activity of proteins.

Catabolic Pathway

Release the energy stored in complex molecules through the breakdown of these molecules into simpler compounds.

What is the role of protein phosphatases?

Remove phosphate groups from proteins.

Anabolic Pathway

Require energy to combine simpler molecules into more complicated ones.

AS the external concentration of K+ is raised, what happens to the Nernst Potential of Potassium?

Resting membrane potential always moves in the same direction as the value of Ek+. If Ek+ becomes less neg, the membrane becomes less neg-depolarizes.

In the cell fractionation, which organelles are the smallest ones isolated in this procedure?

Ribosomes

When are the nucleioli visible? What are assembled here?

Ribosomes are assembled.

Who proposed the fluid mosaic model of membrane structure? When? Describe this model.

S.J. Singer and G. Nicolson proposed it in 1972. It is a phospholipid bilayer with proteins embedded.

How do saturated vs unsaturated fatty acids differ structurally?

SATURATED: all carbons have single covalent bonds w/ other carbons and hydrogens. UNSATURATED: contain 1 or more double C-C bonds

How much of a charge need to be move to change the membrane potential of the cell?

SO little charge has to move For a certain cell size the amount of excess charge is just a very small fraction (1/200,000) of the total number of positive and negative charges in solution within the cytoplasm.

Scanning Electron Microscopy vs. Transmission Electron Microscopy

Scanning- Useful to study the surface of a specimen. Show a 3D image of the surface of a specimen. Transmission- Used to study the internal ultrastructure of cells. Profiles a thin section of a specimen.

Paracrine signaling

Secreting cells sends regulators to target cells and to all cells in the vicinity. Examples are animal cells and growth hormones.

What is membrane potential due to?

Separation of electrical charges across the membrane. work must be performed to separate opposite charges. Separated charges have the potential to do work-hence term membrane potential.

Four functions of microtubules

Shape and support Cell Serve as tracks along which organelles equipped with motor proteins can move Seperate chromosomes during cell division.

Conformation

Shape or arrangement, many receptors undergo a change in conformation when a ligand binds to it

How is signal amplification accomplished in the cell?

Signal ---> reception - (amplification) - transduction - - - - Cellular Response

Transduction

Signal converted to form that can bring about a specific cellular response.

Signal transduction proteins

Signaling molecules create shape change in proteins, and proteins relay a message.

What is the importance of homeostatsis and its relationship to membrane potential.

Since the extracellular conectration of K is very important in determining the resting membrane potential and the rate at which K diffuses out of cells, changes in the concentration of this ion can have drastic consequences.

Function of Mitochondria

Sites of cellular respiration, the metabolic process that generates ATP by extracting energy from sugars, fats, and other fuels.

Function of chloroplasts

Sites of photosynthesis

Diploid

a cell that contains two hapload sets of chromosomes

Incomplete Dominance

a condition in which a trait in an individual is intermediate between the phenotype of the invividual's parents because the dominant allele is unable to express itself fully

Codominance

a condition in which both alleles for a gene are fully expressed

Why is free water concentration the "driving" force in osmosis?

Some water molecules cluster around and solute molecules and are unable to diffuse. The Free water molecules move from high concentration to low concentration until solute concentration is the same on both sides.

What two molecules make up the "uprights"?

Sugar and phosphate

Receptor-mediated endocytosis

Take up of bulk quantities of sparse items. Cholesterol uptake.

What is a glycosidic linkage?

a covalent bond formed between 2 monosaccharides by a dehydration reaction.

Why are the "tails" hydrophobic?

The "tails" are hydrophic (avoid water) because they are hydrcarbon. hydrocarbons are hydrophobic compounds because the great majority of their bonds are relatively nonpolar carbon-to-hydrogen.

Pedigree

a diagram that shows the occurrence of a genetic trait in several generations of a family

Punnett Square

a graphic used to predict the results of a genetic cross

Gamete

a haploid reproductive cell that unites with another haploid reproductive cell to form a zygote

Transduction

The binding of the signal molecule changes the receptor protein in some way. The signal is converted to a form that can bring about a specific cellular response

Do you remember when, in Chapter 4, we said, "To change the structure, change the function"? Explain how this principle applies to sickle-cell disease. Why is the structure changed?

The blood cell is denatured because the weak bonds in the protein are broken so the shape of the blood cell is lost

How can we get a numerical value for equilibrium potential when we know the concentrations of an ion inside and outside a cell?

The bottom equation is one you don't have to do math for. memorize it.

What is a polymer?

a long chain-like molecule, consisting of many similar or identical building blocks linked by covalent bonds.

Ovum

a mature egg cell

membrane potential

The difference in electrical charge (voltage) across a cell's plasma membrane due to the differential distribution of ions. Membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances.

electrochemical gradient

The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane (a chemical force) and the ion's tendency to move relative to the membrane potential (an electrical force).

What determines the direction and strength of the chemical force?

The direction of the chemical force arrow is from the area with the higher concentration towards the area with the lower concentration. The numerical value for the strength of the chemical force is gotten by solving the Nernst Equation. Any time there is a ten fold difference between the inside and outside concentrations the strength of the chemical force is + or - 60mV.

Cytoskeleton

a network of fibers extending throughout the cytoplasm, organize the structures and activities of the cells. Three functions: Support, Motility, and regulation. Three fibers that make up cytoskeleton: microtubules, microfilaments, intermediate filaments.

Spindle

a network of micro-tubules that forms during mitosis and moves chromatids to the poles

Interphase

a period between two miotic or meiotic divisions during which the cell grows, copies its DNA, and synthesizes proteins

Meiosis

a process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells

Given the internal environment of a lysosome, what transport protein might you expect to see in its membrane?

The internal environment of a lysosome is acidic, so it has a higher concentration of H+ than does the cytoplasm. Therefore, you might expect the membrane of the lysosome to have a proton pump such as that shown in Figure 7.20 to pump H+ into the lysosome.

What is the Nerst for Cl- when there is no Net Pumping of Cl- into or Out of the cell

The membrane potnetial will determin the concentration of Cl-, instead of the Cl- determing the membrane potential.

Besides mutation, which changes the primary structure of a protein, protein structure can be changed by denaturation. Define denaturation, and give at least three ways a protein may become denatured.

a protein unravels and loses its shape because the bonds between the proteins are destroyed -change in pH -change in temp -chemical -salt concentration

What is meant by membrane fluidity? Describe the movements seen in the fluid membrane?

The phospholipids are free to move along the plane of the lipid bilayer. Unanchored proteins may also move slowly .

Signal Transduction Pathway

The process by which a signal on a cells surface is converted into a specific cellular response through a series of steps

Explain how feedback inhibition prevents a cell from wasting chemical resources

The product of a pathway acts as an allosteric inhibitor of an enzyme early in the pathway

chromatin

long strands of DNA found in the eukaryotic cell nucleus; condense to form chromosomes

Name the correct carbohydrate for each? Malt sugar; used to brew beer

maltose

What happens during hypopolarization or Depolarization?

membrane becomes less neg inside the and less pos outside ex -80mV to -50mV When the cell is depolarized there is a fall or reduction in the membrane potential since the absolute differences in the potential between the inside and the outside of the cell has decreased.

What happens to the cell during hyper-polarization?

membrane becomes more neg inside and more positive outside changes from -80mV to-90mV

What is membrane potential? Which side of membrane is positive?

membrane potential = voltage difference; an electrical potential difference across a membrane; from the Na/K pump, the outside of the cell membrane is more +

Let's look at carbohydrates, which include sugars and starches. First, what are the monomers of all carbohydrates?

monosaccharides (simple sugars)

Movements of ion can change the membrane potential- If a pos ion move out of a cell the cell will become more ______. If a pos ion moves into a cell the cell will become more_______.

more neg less neg

What happens if the extracelluar concentration of Na is increased, the Nerst potential becomes...

more positive and the membrane potential becomes slightly negative.

Multiple Alleles

more than two alleles for a genetic trait

Sex Chromosome

ne of the pair of chromosomes that determine the sex of an individual

A neg membrane potential woud exert an electrical force that pushed ____ ions out of the cell.

neg ions

The steps (or rungs) of the ladder are made up of what?

nitrogen bases held together by hydrogen bonds

Allele

one of the alternative forms of a gene that governs a characteristic such as hair color

Chromatid

one of the two strans of a chromosome that become visible during meiosis of mitosis

sex chromosome

one of two chromosomes of the 23rd pair of human chromosomes, which determine an individual's gender

P Generation

parental generation, the first two individuals that mate in a genetic cross

Compare permeability with conductance.

permeability is a property of the membrane conductance depnds on poreptiess of both the membrane and concnetration of ions in solution. Example: a membrane could have a very high permeability to K+ but if there are no K+ ions in solution the conductance of the membrane will be zero

What are the 3 parts of a nucleotide?

phosphate, deoxyribose sugar, nitrogen-containing base

Name two unsaturated fats.

plant fats and fish fats

Define dipeptide

polymer of 2 amino acids linked by a peptide bond

Define polypeptide

polymer of many amino acids linked by a peptide bond

Whenever the membrane potential is neg the electrical force will draw ___ ions in to the cell.

positive ions

turgid

pressurized state of a plant cell resulting from osmotic intake of water pressing the cell wall against the cell membrane and the membrane against the wall

sexual reproduction

process by which cells from two different parents unite to produce the first cell of a new organism

Apoptosis

programmed/controlled cell suicide, apoptosis can be triggered by STP's like a death-signaling ligand.

What is the purpose of the phospholid bilayer in membranes

provides permeability barrier and allows proteins to stay in place; excludes water-soluble molecules from nonpolar interior of bilayer and cell

How is Na k pump necessary to regulate cell volume

pumping Na out of the cell, it decreaes the osmotic pressure in the cytoplasm and incresase the osmotic pressue of teh ECF

centromere

region where two sister chromatids are joined tightly together

DNA is made up of what?

repeating molecules called nucleotides

Sexual Reproduction

reproduction in which gametes from two parents unite

Asexual Reproduction

reproduction that does not involve the union of gametes and in which a single parent prodices off-spring that are genetically identical to the parent

asexual reproduction

reproduction that does not involve the union of gametes and in which a single parent produces offspring that are genetically identical to the parent

gamete

sex cell; sperm or egg

What is the electrochemical gradient?

since ions are acted upon by two different forces, we must know the strngths and directions of both forces to determin the electrochemical gradient. ions will diffuse down their electrochemical gradients.

Water potential is the combined effects of ______________ concentration and ___________ ______________; this determines water movement.

solute concentration; physical pressure

Name the correct carbohydrate for each? Has 1-4 B glucose linkages

starch

flaccid

state of a plant cell placed in an isotonic solution

Have you noticed that all the sugars end in -ose? This root word means _______.

sugar

What parts of the nucleotides make up the sides (backbone) of the "ladder"?

sugar and phosphate

What parts of the nucleotides make up the rungs of the "ladder"?

the bases

How do you know it is unsaturated? Know how to identify a unsaturated lipid.

the carbon chain has a bend which shows a double bond between

Zygote

the cell that results from the fusion of gametes; a fertilized egg

What are the two forces that drive the diffusion of ions across the membrane? What is the combination of these forces called?

the chemical force (concentration gradient) and the electrical force (repulsion & attraction)

Test Cross

the crossing of an individual of unknown genotype witha homozygous recessive indivudual to determine the genotype of the unknown individual

osmosis

the diffusion of water across a selectively permeable membrane which goes from the side containing the lower concentration of solute to the side containing higher concentration in absence of differences in pressure or volume

Cytokinesis

the division of the cytoplasm of a cell; folllows the division of the cells nuceleus by mitosis of meiosis

Genotype

the entire genetic makeup of anorganism; also the combination of genes for one or more specific traits

Crossing-Over

the exchange of genetic material between homologous chromosomes during meiosis; can result in genetic recombination

F1 Generation

the first generation of offspring obtained from an experimental cross of two orgnasims

Law of Independent Assortment

the law that states that genes separate independently of one another in meiosis

Cell Cycle

the life cycle of a cell; in eurkaryotes, it consists of a cell growth period in which DNA is synthesized and a cell division period in which mitosis takes place

Probability

the likeliy hood that a possible future event will occur in any given instance of the event; the mathmatical ratio of the number of times one outcome of any event in likely to occur to the number or bossible outcomes of the event

The flow of genetic information is from DNA -> RNA -> protein. Use this figure to explain the process. Label the nucleus, DNA, mRNA, ribosome, and amino acids.

the mRNA interacts with the cell's protein-synthesizing machinery to direct the ordering of amino acids in a polypeptide (occurs in ribosome, located in the cytoplasm). mRNA moves information and directions from the nucleus to cytoplasm where the ribosomes are. The ribosomes then creates proteins with the amino acids with the information and directions brought by the the mRNA.

Sperm

the male sex cell

passive transport

the movement of substances across a cells' membrane without the expenditure of energy

Define diffusion

the net movement of dissolved molecules or other particles from a region where they are more concentrated to a region where they are less concentrated

Heredity

the passing of genetic traits from parent to offspring

electrical gradient

the potential difference across membrane, slightly negative charge on inner surface and a positive charge on outer surface

Spermatogenesis

the process by which male gametes form

Oogenesis

the production, growth, and maturation of an egg or ovum

Independent Assortment

the random distribution of the pairs of genes on different chromosomes to the gametes

Centromere

the region of the chromosome that holds the two sister chromatids together during mitosis

Genetics

the science of heredity and of the mechanisms by which traits are passed from parents to offspring

F2 Generation

the sencong generation of offspring, obtained from an experimental cross of two organisms

plasmolysis

the shrinking of a plant cell in a hypertonic solution such that it pulls away from the cell wall

locus

the specific site of a particular gene on its chromosome

Recessive

the trait that doesnt show

Dominant

the trait that shows

Fertilization

the union of a male and female gamete to form a zygote

Study your sketch from question 34. Why are the tails from the phospholipid bilayer all located in the interior?

they are in contact with each other and remote from water because they are hydrophobic

What base attaches to adenine?

thymine

Describe major functions of membrane proteins - Transport - Enzymatic Activity - Cell Surface Receptor (signal transduction) - Cell-surface (cell-cell) recognition cell-to-cell adhesion (intercellular joining) - attachment to cytoskeleton and ECM

transport - transmembrane proteins that move specific molecules through the membrane in a series of conformational changes or providing a tunnel (ie carrier proteins, Na/K pump, etc.) - Enzymatic activity: carry out many chemical reactions on the interior surface of the plasma membrane Cell Surface Receptor (signal transduction) - transmembrane proteins that bind signal molecules which in turn induces activity within the cell Cell-surface recognition- glycoproteins such as the MHC is used for cell recognition by creating a protein/carbon chain characteristic of an individual Cell to cell adhesion - proteins that "glue" cell together by forming temporary interactions and more permanent bonds attachment to cytoskeleton and ecm: surface proteins that interact with other cells and are often anchored to the cytoskeleton by linking proteins

sister chromatids

two identical daughter strands of a replicated parent chromosome joined at the middle by a centromere

What is a gene?

units of genetic material that codes for a specific trait called nucleic acids?

What are other examples of steroids?

vertebrate sex hormones

Are transport proteins specific? Cite an example that supports your response

yes - transport proteins are specific Na/K pump only move Na out of the cell and K into the cell

A haploid cell is a cell A. in which the genes are arranged haphazardly B. containing only one copy of each chromosome C. that has resulted from the process of mitosis D. with twice the number of chromosomes of a diploid cell E. None of the above.

B

When restriction enzymes make cuts with ____ ends, the DNA sequences can form ____ bonds with complementary sequences. A. sticky, covalent B. sticky, hydrogen C. blunt, ionic D. blunt, hydrogen E. blunt, covalent

B

In the formation of a triglyceride, __ molecule(s) combine with __ molecule(s) to form a triglyceride plus __ molecule(s) of water. A. 1; 1; 1 B. 1; 3; 1 C. 1; 3; 3 D. 3; 3; 3 E. 3; 1; 3

C

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane into the inter membrane space, the result is the A. formation of ATP B. reduction of NAD+ C. creation of a proton gradient D. restoration of the Na+K+ balance across the membrane E. reduction of glucose to lactic acid

C

Which of the following changes affects more than a single amino acid in a sequence? A. a silent mutation B. a missense mutation C. a frameshift mutation D. Both A and B E. Both B and C

C

Receptor-Mediated Endocytosis

Coated pits contain receptors that attach to specific molecules, engulf and put into vesicle.

Which of the following statements is inconsistent with the first and second law of thermodynamics? A. Living organisms can produce energy. B. Chemical energy may be converted to light energy. C. The total energy of a system is available to do work. D. Potential energy may be used to do work. E. Both a and c

E

Which of the following types of interactions is beneficial to one partner and detrimental to the other partner? A. competition B. amensalism C. commensalism D. mutualism E. parasitism

E

Which of the following would be best explained by directional selection? A. Human birth weight in contemporary industrial societies B. The long horns of Texas longhorn cattle C. The persistent decline in the leg size of primitive whales D. Both A and B E. Both B and C

E

You are monitoring the diffusion of a molecule across a membrane. An internal concentration of _____ and an external concentration of _____ will result in the fastest rate of diffusion. A. 5; 60 B. 60; 5 C. 35; 40 D. 50; 50 E. Either a or b

E

How does that affect fluidity?

Fatty acid tails are very hydrophobic and interact tightly w/ each other to avoid water = saturated= membrane rigid and viscous Double bonds in unsaturated fatty acid tails put kinks (can't pack tightly) = unsaturated = membranes more fluid

What is the electrochemical gradient?

It is the diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane (a chemical force) and the ion's tendency to move relative to the membrane potential (an electrical force).

Why are many unsaturated fats liquid at room temperature?

The kinks where the cis bonds are located prevent the molecules from packing together closely enough to solidify at room temperature.

Free Energy

The portion of a system's energy available to perform work when the system's temperature and pressure are uniform.

How is specificity accomplished in cell signaling?

The response of a particular cell to a signal depends on it's particular collection of: signal receptor proteins, relay proteins & proteins needed to carry out the response

Monohybrid Cross

a cross between individuals that involves one pair of contrasting traits

somatic cells

all the cells of your body except your sex cells

Clone

an organism that is produced by asexual reproduction and that is genetically identical to its parent; to make an identical copy

Phenotype

an organisms's appererence or other detectable characteristic that resilts from the organisms genotype and the environemtn

Name the correct carbohydrate for each? Glucose + ______________ form sucrose

fructose

water moves from areas of _____________ water potential to areas of ____________ water potential

high; low

The gradual process of environmental change and species replacement is called A. succession B. zonation C. area affect D. predation E. commensalism

A

Which of the following structures occupies the largest volume in a mature plant cell? A. vacuole B. chloroplast C. peroxisome D. mitochondrion E. ribosome

A

An engineered DNA molecule that contains sequences from cattle and sequences form bacteria would be considered to be _____ DNA. A. transgenic B. recombinant C. electroporated D. genomic E. None of the above

B

Bacteria engage in genetic transfers after a thin projection called a ______ extends from one cell to another. A. chromosome B. plasmid C. sex pilus D. highly packed linear strand of DNA E. chiasmata

C

Different forms of a gene are called A. traits B. phenotypes C. genotypes D. alleles E. None of the above

D

Transcription of eukaryotic genes requires A. binding of RNA polymerase to the promoter B. binding of several transcription factors C. capping of mRNA D. Both A and B E. None of the above

D

Which part of the cell acts as the conducting materal?

The ECF and cytoplasm

Type of Protein: Enzyme -what is the function? -give an example

-Accelerate chemical reactions -Maltase, pepsin, sucrase

Circle the three classes that are called macromolecules. Define macromolecule.

-Carbohydrates, Proteins, Nucleic Acids -Macromolecules are extremely large on the molecular scale, sometimes consisting of thousands of atoms.

Why is water balance important for cells that have walls as compared to cells without walls?

-Cell Walls push back on the cell when they become turgid -Cells without walls cannot push back, they can burst.

What is cotransport and why is it an advantage in living systems?

-Cotransport is a substance pumped across a membrane, and does work as it diffuses back across the membrane. - ATP indirectly provides energy for co-transport

How has our understanding of membrane permeability changed since the discovery of aquaporins?

-aquaporins allow a tremendous amount of water to pass through a hydrophobic membrane at a fast rate. - other ions and polar molecules pass through transport proteins

Level of Protein Structure: Secondary (II^0) -explanation -Alpha helix -Beta pleated sheets -Alpha example Beta example

-coils and folds resulting from hydrogen bonds between the repeating constituents of the polypeptide backbone -coils -folds -ex. protein in hair -ex. protein in silk

What is the structure of DNA?

-composed of polynucleotides -- have a phosphate group, deoxyribose sugar and a nitrogen containing bases (adenine, thymine, cytosine and guanine) -Has a doubled helix that is formed by hydrogen bonds between polynucleotides -Densely compacted into chromosomes to fit into nucleus

What is DNA?

-deoxyribonucleic acid -contains information for the cell and genetic material -has a phosphate group/phosphoric acid, deoxyribose sugar and nitrogen containing bases (adenine, thymine, cytosine, guanine)

-What 2 monosaccharides form sucrose? -Where is sucrose found?

-glucose and fructose -table sugar

-What 2 monosaccharides form lactose? -Where is lactose found?

-glucose and galactose -milk sugar

What is the structure of RNA?

-has polynucleotides -- have a phosphate group, ribose sugar and nitrogen containing bases (adenine, uracil, cytosine, guanine) -single stranded -moves out of nucleus to perform protein synthesis

How do glycolipids and glycoproteins help in cell to cell recognition?

-identifies foreign cells -important in sorting types of cells in embryos - designates type A, B, AB and O in blood groups

Level of Protein Structure: Tertiary (III^0) -explanation -example

-interactions among various R groups -transthyretin polypeptid

What are the functions of DNA?

-stores an organisms genetic material in the nuclei -replicates itself when dividing -provides code or template for the particular sequencing of amino acids that bond together and make a protein

Study the figure. See if you can understand why some R groups are nonpolar, some polar, and others electrically charged (acidic or basic). If you were given an R group, could you place it in the correct group? Work on the R groups until you can see common elements in each category. *THIS IS IMPORTANT KNOW HOW TO IDENTIFY* -diagram found from question 43

-tells you how to identify and some examples on diagram from question 43

Describe what happens to a transport vesicle and its contents when it arrives at the Golgi.

...

Cellular membrane contain four components

1. phospholipid bilayer 2. transmembrane proteins 3. Internal protein network providing structural support 4. cell-surface markers (glycoproteins and glycolipids)

A hypothetical population not constrained by environmental limits would experience _______ growth. A. multiplicative B. subtractive C. additive D. no E. diverse

A

A researcher inserts a DNA segment at the BamHI recognition site within a plasmid; this site is located within the tetracycline resistance gene. This plasmid also has a gene for ampicillin resistance. Following DNA transformation, the researcher must differentiate the bacteria that have taken up the recombinant DNA from those that have taken up either the DNA segment only or have taken up intact plasmids. In order to do so, the researcher should select the bacteria that A. will grow on ampicillin but are sensitive to tetracycline B. are sensitive to both antibiotics C. are resistant to both antibiotics D. will grow on tetracycline but are sensitive to ampicillin E. grow only on an enriched medium

A

According to Charles Birch's experiments in which temperature and humidity were manipulated to determine ideal conditions for rice weevils and grain borers, grain should be kept in a _______ environment to deter these insects. A. cool and dry B. cool and wet C. warm and dry D. warm and wet E. No condition was found to inhibit these insects.

A

After DNA replication, each chromosome has _____ molecule(s) of DNA called ____ that after separation are known as _____ chromosomes. A. two; sister chromatids; daughter B. four; sister chromatids; daughter C. two; daughter chromatids; sister D. four; sister chromosomes; daughter E. two; daughter chromosomes; sister

A

All cells in a multicellular organism A. contain the same genome B. randomly express parts of the genome C. have the same function D. express the same parts of the genome at the same time E. from all the same proteins

A

At the end of DNA replication, two DNA molecules are produced, each one consisting of a parental DNA strand and a new DNA strand. This process is known as A. semiconservative replication B. conservative replication C. dispersive replication D. fission E. the transforming principle

A

Bacteria typically have _____, whereas eukaryotes have ______. A. one chromosome that is usually circular; many chromosomes that are linear B. several chromosomes that are circular; many chromosomes that are linear C. one chromosome that is linear; many chromosomes that are circular D. two chromosomes that are usually circular; eight chromosomes that are linear E. None of the above

A

Cells are placed in a solution of glucose in which the concentration of glucose is gradually increased. At first, the rate at which glucose enters the cells is found to increase as the concentration of the glucose solution is increased. But when the glucose concentration of the solution is increased above 10 M, the rate no longer increases. Which of the following is likely the mechanism for glucose transport into these cells? A. facilitated diffusion via carrier protein B. facilitated diffusion via channel protein C. pinocytosis D. secondary active transport E. hydrolysis

A

Compared with fermentation, the aerobic pathways of glucose metabolism produce A. more ATP B. pyruvate C. fewer protons for pumping in the mitochondria D. less CO2 E. more oxidized coenzymes

A

During initiation, the sequence of DNA to which RNA polymerase binds most tightly is the A. promoter B. poly C center C. enhancer D. operator site E. minor groove

A

During the formation of a peptide linkage, a(n) ____ is formed. A. molecule of water B. disulfide bridge C. hydrophobic bond D. hydrophilic bond E. ionic bond

A

How does a nucleus in G2 differ from a nucleus in G1? A. The G2 nucleus has twice the amount of DNA as the G1 nucleus. B. DNA synthesis occurs only in G1 phase. C. Inactive cells are arrested only in G2 phase. D. During G2, the cell prepares for S phase. E. All of the above.

A

If a red blood cel with an internal salt concentration of about 0.85 percent is placed in a saline solution that is 4 percent, the A. cell will lose water and shrivel B. cell will gain water and burst C. turgor pressure in the cell will increase greatly D. turgor pressure in the cell will decrease greatly E. cell will remain unchanged

A

If b, the per capita birth rate, is higher than d, the per capita death rate, which of the following will occur? A. The population will grow because r > 0. The population will go extinct because r = 0. C. The population will grow because r < 0. D. The population stays the same size because r = 0. E. The results cannot be calculated from the information provided.

A

In a repressible operon, the repressor molecule A. must first be activated by a co-repressor B. can repress the transcription of the operon on its own C. is a molecule made from the operon D. binds to the mRNA E. must first be made negative to control the operon

A

In a trophic level, primary producers A. receiver their energy level from the sun B. decompose waste products C. receiver their energy from minerals in the soil D. receive their energy by consuming animals E. receiver their energy by consuming plants

A

In biological membranes, the phospholipids are arranged in a _____, with the _____. A. bilayer; fatty acids pointing toward each other B. bilayer; fatty acids facing outwards C. single layer; fatty acids facing the interior of the cell D. single layer; phosphorus-containing region facing the interior of the cell E. bilayer; phosphorus groups in the interior f the membrane

A

In both photosynthesis and respiration, protons are pumped across a membrane during A. electron transport B. photolysis C. CO₂ fixation D. reduction of O₂ E. glycolysis

A

In eukaryotes, the first amino acid in a growing polypeptide chain is always ____ because the only codon for this amino acid is also the ____ codon. A. methionine, start B. tryptophan, stop C. alanine, start D. alanine, stop E. tryptophan, start

A

In photosynthetic formation of ATP, the enzyme ATP synthase couples the synthesis of ATP to A. the diffusion of protons B. the reduction of NADP+ C. the excitation of chlorophyll D. the reduction of chlorophyll E. CO₂ fixation

A

Most of the biomass of a grassland is found in the A. green plants B. water C. animals D. the soil E. the atmosphere

A

Nucleic acids and proteins are both polymers made of a certain set of monomers. ____ are to nucleotides as side chains are to amino acids. A. nitrogenous bases B. phosphate ions C. ribose/deoxyribose D. nucleosides E. hydroxyl groups

A

Oils and fats A. are triglycerides B. have glycosidic linkages C. form membranes D. are good for you in large amounts E. all contain the same fatty acids

A

Plants are green because A. chlorophylls absorb blue and orange-red wavelengths of light and reflect green and light B. chloroplasts transmit green light C. energized chlorophyll a emits green light D. plants do not possess green pigment E. chlorophylls absorb green light

A

Segregation of alleles occurs A. during gamete fertilization B. at fertilization C. during mitosis D. during the random combinations of gametes to produce the G2 generation E. only in monohybrid crosses

A

Suppose that there is a mutation in the lac operon that prevents the repressor from binding to the operator. In the absence of lactose, the genes of the operon will be ____. In the presence of lactose, the genes will be ____. A. on, on B. on, off C. off, on D. off, off E. None of the above; in both cases the presence or absence of the co-repressor would dictate whether the genes are on or off.

A

Table salt, NaCl, is neutral. When dissolved in water, NaCl A. separates to form Na+ and Cl- ions that interact with water molecules B. separates to form Na- and Cl+ molecules C. does not separate, but interact with water molecules D. remains as NaCl (does not dissociate) E. separates to form Na+ and Cl- ions that do not interact with water molecules

A

The "building blocks" of polysaccharides are ___________, and the blocks are covalently linked together by ________. A. monosaccharides; glycosidic linkages B. disaccharides; triple bonds C. glycerol and fatty acids; glycosidic linkages D. oligosaccharides; glycosidic linkages E. amino acids; triple bonds

A

The TATA box is a(n) A. sequence found i the promoter region of many genes B. general transcription factor C. enhancer consensus sequence D. activator sequence necessary for proper translation E. None of the aboe

A

The ______ was the first unifying principle of biology. A. cell theory B. spontaneous generation theory C. germ theory of disease D. theory of genetic determinism E. law of Ohno

A

The component of aerobic respiration that produces the most ATP per mole of glucose is A. the electron transport chain B. the citric acid cycle C. glycolysis D. lactic acid fermentation E. alcoholic fermentation

A

The electron transport chain contains four large protein complexes. These proteins A. are embedded in the inner membrane of the mitochondrion B. change in a similar way when reduced C. regulate the passage of water through the respiratory chain D. oxidize NADH E. complete oxidation of pyruvate to acetate

A

The expression of the lac structural genes is _____ when lactose is absent from the culture medium and is _____ when lactose is added because lactose binds to the _____ and inactivates it. A. low, high, lac repressor B. high, low, lac operon C. low, high, lac promoter D. high, low, lac operator E. low, high, lac operator

A

The first rise in human population growth was due to A. advances in agriculture B. antibiotics C. the "Green Revolution" D. bubonic plague E. All of the above.

A

The four large protein complexes in the electron transport chain A. transport electrons B. ensure the production of water and oxygen C. regulate the passage of water through the chain D. oxidize NADH E. None of the above

A

Which of the following is the driving force for facilitated diffusion? A. concentration gradient B. ATP hydrolysis C. ADP hydrolysis D. phosphorylation E. GTP-GDP exchange

A

Which of the following pairs of phase and event does not match? A. Prophase: duplication of centrosome B. Metaphase: formation of equatorial plate C. Telophase: formation of nuclear envelopes D. Interphase: replication of DNA E. Anaphase: separation of chromatids

A

Which of the following statements about genetic drift as an evolutionary factor is true? A. It is more significant in a population with small numbers than in a population with large numbers. B. It is responsible for selection mutations. C. It is connected to the movements of alleles between populations of a single species. D. Its strength is proportional to the size of a population: the larger the population, the greater the force E. both A and B

A

Paracrine Signaling

A secreting cell acts on nearby target cells by discharging molecules of a local regulator into the extracellular fluid

How do some membrane proteins that actively transport ions contribute to the membrane potential?

An example is the sodium potassium pump. Notice in Figure 7.18 that the pump does not translocate Na+ and K+ one for one, but pumps three sodium ions out of the cell for every two potassium ions it pumps into the cell. With each "crank" of the pump, there is a net transfer of one positive charge from the cytoplasm to the extracellular fluid, a process that stores energy as voltage.

What is the energy source that supplies the energy for most active transport?

As in other types of cellular work, ATP supplies the energy for most active transport. One way ATP can power active transport is by transferring its terminal phosphate group directly to the transport protein. This can induce the protein to change its shape in a manner that translocates a solute bound to the protein across the membrane. One transport system that works this way is the sodium-potassium pump, which exchanges Na+ for K+ across the plasma membrane of animal cells.

Why does a higher than normal excellular concentraion of K hyper kalemia depolarize a cell making the cell's resting membrane potential less negative?

At rest a cell is much morep ermeable to K than it is to na resting potential is largely neg bc intracellular con of K is much higher than extracellular conc and the cell membrane is slightly permebale to K when K flows down its con gradient, leaving the cell, the cell membrane would become more neg, which this electrical force would tend to oppose the movement of K out of the cell. if the membrane potnetial became less negative for any reason the electrical force holding K in the cell would decrease, so additonal k would leave the cell making the cell more neg again As EC con of K is raised, the cheomical force driving K out of the cell decreases in size. Ek is the chemical force so it decreases in size. If the extracellular con was raised to the level of the intracelluar con, Ek wwould equal zero since there would be no chemical force on the ion this value is only found post mortem.

A pea plant with red flowers is test crossed, and one-half of the resulting progeny have red flowers, while the other half has white flowers. Therefore, the genotype of the test-crossed parent was A. RR B. Rr C. rr D. either RR or rr E. This cannot be answered without more information.

B

A small population of sawflies that was once connected to a larger one but is now isolated is no longer experiencing A. enhanced genetic drift B. gene flow C. reproductive isolation D. natural selection E. genotypic equilibrium

B

An organism A. can be generated from nonliving materials today B. is either a prokaryote or a eukaryote C. cannot do biological work D. does not contain genetic information E. must contain more than one cell

B

At a certain locus of the human genome, 200 different alleles exist in the population. Each person has at most ___ allele(s). A. 1 B. 2 C. 100 D. 200 E. 400

B

Cells that do not divide are usually arrested in A. S B. G1 C. G2 D. M E. prophase

B

DNA is _____ charged due to the presence of a _____ group. A. negatively, methyl B. negatively, phosphate C. negatively, carbon D. positively, methyl E. positively, phosphate

B

During the fermentation of one molecule of glucose, the net production of ATP is _____ molecule(s). A. one B. two C. three D. six E. eight

B

Enzymes are biological catalysts that function by A. increasing free energy in a system B. lowering activation energy of a reaction C. lowering entropy in a system D. increasing temperature near a reaction E. altering the equilibrium of the reaction

B

For a covalent bond to be polar, the two atoms that form the bond must have A. similar electronegativities B. different electronegativities C. different atomic weights D. the same number of electrons E. different melting points

B

Humans have 46 chromosomes and ______ autosomes. A. 23 pairs of B. 22 pairs of C. 1 pair of D. 45 E. 16

B

If a population with two alleles is at Hardy-Weinberg equilibrium and the frequency of one allele is 0.7, what is the heterozygote frequency? A. 0.7 B. 0.42 C. 0.3 D. 0.21 E. Insufficient information is given to answer the question

B

If a shallow pan is filled with water, a drop of red ink is placed in one end of the pan, and a drop of green ink is placed in the other end, which of the following will be true at equilibrium? A. The red ink will be uniformly distributed in one half of the pan, and the green ink will be uniformly distributed in the other half of the pan. B. The red and green inks will be uniformly distributed throughout the pan. C. Each ink will move down its concentration gradient. D. The concentration of each ink will be higher at one end of the pan than at the other end. E. No predictions can be made without knowing the molecular weights of the pigment molecules.

B

If you set up an experiment pairing different species of Paramecium together, under what circumstances would one species be least likely to go extinct? A. amenslaism B. mutualism C. consumer-resource interaction D. interspecific competition E. intraspecific competition

B

In a sickle-cell disease, one amino acid is substituted for another. This type of mutation is referred to as a _____ mutation. A. nonsense B. missense C. frame-shift D. temperature sensitive E. silent

B

In a species of tortoise, foot size (big or small) is controlled by one gene, while shell shape (round or lumpy) is controlled by another gene. Suppose that a big-footed lumpy-shelled tortoise mates with a small-footed round-shelled tortoise. Eight offspring result: four big-footed round-shelled tortoises. (Assume that the parents are not necessarily homozygous for each allele.) Which statement about the inheritance of the shell shape in tortoises is most likely to be correct, given your genetic analysis of the tortoise family? A. Lumpy is dominant to round. B. Round is dominant to lumpy. C. Round and lumpy are codominant. D. Both A and C E. This cannot be answered without more information.

B

In noncyclic photophosphorylation, electrons from _____ replenish chlorophyll molecules that have given up electrons. A. CO₂ B. water C. NADPH + H protons D. O₂ gas E. None of the above

B

Nutrients A. are synthesized by cells B. are broken down inside cells C. require energy to be broken down D. do not play a role in the synthesis of complex molecules E. are broken down outside of cells

B

Oils melt at a lower temperature than fats because A. oil are made by plants B. fats contain more saturated fatty acids than oils C. fats contain more unsaturated fatty acids than oils D. fats are common in animals E. oils and fats are not the same type of macromolecule

B

One component of species diversity is the number of species in a community, which is also known as A. species evenness B. species richness C. net primary productivity D. trophic interactions E. gross primary productivity

B

Plastids are A. very similar to mitochondria B. present in nearly all plant cells C. present in photosynthetic prokaryotes D. present in all eukaryotes E. always green

B

Recombinant DNA technology requires not only getting the DNA into the cell, but also getting it to replicate appropriately. In this process, the specificity of which of the following enzymes can present a challenge? A. DNA ligase B. DNA polymerase C. RNA polymerase D. reverse transcriptase E. replicase

B

Scientific explanations for a natural phenomenon A. are a reflection of how things ought to be B. do not refer to religious or spiritual explanations C. cannot be tested D. cannot be rejected E. may be based on data that cannot be reproduced

B

Single-celled animals, such as amoebas, engulf entire cells for food. This manner of "eating" is called A. exocytosis B. endocytosis C. facilitative transport D. active transport E. osmosis

B

Solution X is hypotonic relative to solution X has a solute concentration that is _____ solution Y. A. greater than that of B. lower than that of C. the same as that of D. All of the above E. None of the above

B

Termination of transcription involves a A. stop codon B. terminator sequence C. termiproteator D. hairline slip E. series of As

B

The NADPH required for the reduction of 3PG to G3P comes from A. the dark reactions B. the light reactions C. the synthesis of ATP D. the Calvin cycle E. oxidative phosphorylation

B

The advantage of controlled experiments is that A. the hypothesis is proven right B. all variables are held constant except for one C. patterns can be predicted D. a massive amount of data can be synthesized E. Both a and c

B

The difference between birth rate and death rate is an estimate of a population's A. longevity B. growth rate C. fecundity D. survivorship E. None of the above.

B

The difference between the BD growth model and the BIDE model is the inclusion of ______ in the BIDE model. A. birth and logistic growth B. immigration and emigration C. death and carrying capacity D. inbreeding and evolution E. natural selection and continental drift

B

The drug 2,4-dinitrophenol (DNP) destroys the proton gradient across the inner mitochondrial membrane. What would be the effect of incubating isolated mitochondria in a solution of DNP? A. Oxygen would no longer be reduced to water. B. No ATP would be made during transport of electrons down the respiratory chain. C. Mitochondria would show a burst of increased ATP synthesis. D. Glycolysis would stop. E. Mitochondria would switch from glycolysis to fermentation.

B

The enzyme DNA ligase is required continuously during DNA replication because A. fragments of the leading strand must be joined together B. fragments of the lagging strand must be joined together C. the parental strands must be joined back together D. 3' deoxynucleoside triphosphates must be converted to 5' deoxynucleoside triphosphates E. the complex of proteins that work together at the replication fork must be prevented from falling apart

B

The molecules that function to replicate DNA in the cell are A. DNA nucleoside triphosphates B. DNA polymerases C. nucleoside polymerases D. DNAses E. ribonucleases

B

The presence of _______ means that substances must pass through, rather than between, the epithelial cells that form the lining of the small intestine. A. gap junctions B. tight junctions C. desmosomes D. plasmodesmata E. both a and b

B

The process that converts glucose to pyruvate, generating a small amount of ATP but no carbon dioxide, is called A. pyruvate oxidation B. glycolysis C. the citric acid cycle D. the respiratory chain E. gluconeogenesis

B

When a molecule loses hydrogen atoms (as opposed to hydrogen ions), it becomes A. reduced B. oxidized C. redoxed D. hydrogenated E. hydrolyzed

B

Which of the following statements about duplications and translocation is true? A. Translocations involve the loss of a chromosomal segment, whereas duplications involve the addition of an entire chromosome. B. Duplications involve the breaking and swapping of DNA segments on homologous chromosomes, whereas translocations are reciprocal exchanges on non homologous chromosomes. C. Translocations involve the breaking and insertion of DNA segments in reverse order, whereas duplications are the breaking of DNA at different points on the chromosome. D. Duplications lead to duplications of the chromosome, whereas translocations involve the swapping of chromosome segments. E. Translocations result in the loss of chromosomal segments, whereas duplications result in significant additions to non homologous chromosomes.

B

Which of the following statements best describes the difference between an element and a molecule? A. An element is composed of atoms; a molecule is not. B. An element is composed of only one kind of atom; molecules can be composed of more than one kind of atom. C. Elements always have lower atomic weights than molecules. D. An element is unstable; molecules are stable. E. Elements exist in nature only as parts of molecules.

B

You are a biologist contending with a novel species that has just been detected in a lake. The spiny water flea competes for algae with other small organisms and is not consumed by larger organisms. What would be your prediction about the population of spiny water fleas in the lake? A. They are not likely to survive. B. The population will initially grow quickly but will eventually be limited. C. The population will grow multiplicatively with no limit. D. All organisms in the lake will go extinct as a result of the invasion. E. None of the above.

B

You know that the population density of ticks in an area is 100 ticks per square meter. From this information, how is population size calculated? A. Subtract the carrying capacity from 100 B. Multiply 100 by the occupied area C. Multiply 100 by the birth rate, then subtract the death rate D. Add logistic growth to 100 E. Divide 100 by the birth rate

B

You're most measuring resource allocation in white-footed mice under different resource availabilities. If resources are abundant, what is the most likely allocation pattern among reproduction, growth, defense, and homeostasis? A. Allocation to reproduction will be highest to maximize population growth. B. Resources will be equally allocated in all categories. C. Allocation to homeostasis would be highest to maximize health. D. Allocation to defense would be lowest as defense would not be needed. E. Resource allocation cannot be determined from the information provided.

B

How does one measure the memrbane potentail of a cell?

By placing an intracelluar electrode inside the cell and an extracellular electod in the ECF. A voltmeter could then mearuse the potental difference across the cell membrane. outside the cell is considered OmV inside of a cell at rest is always neg relative to the outside so the cell memrbane potential is a neg number.

A restriction enzyme cuts a 25,700 bp segment of DNA into three fragments. Fragment A is 5,800 bp and fragment B is 6,600 bp. How long is fragment C, and which of the fragments will move the farthest in an electrophoresis gel? A. 12,400 bp, fragment A B. 12,400 bp, fragment C C. 13,300 bp, fragment A D. 13,300 bp, fragment C E. 19,900 bp, fragment C

C

ATP is produced during the light reactions via A. CO₂ fixation B. chemiosmosis C. reduction of water D. glycolysis E. noncyclic electron flow from photosystem I

C

According to the chemiosmotic theory, the energy for the synthesis of ATP as electrons flow down the respiratory chain is provided directly by the A. hydrolysis of GTP B. reduction of NAD+ C. diffusion of protons D. reduction of FAD E. hydrolysis of ATP

C

All living organisms can be assigned to three separate A. species B. genus groups C. domains D. ancestors E. genomes

C

Amensalism is the type of interaction in which A. two organisms use the same limited resources B. one participant benefits and the other is unaffected C. one participant is harmed but the other is unaffected D. both participants benefit E. one participant is harmed while the other benefits

C

Bacteria protect themselves from their own restriction enzymes by A. means of their blunt ends B. means of their sticky ends C. adding methyl groups at restriction sites D. means of DNA ligase E. transforming themselves

C

Choose the description that best describes the what happens between the processing of Okazaki fragments and the replication of the lagging strand. A. DNA ligase replaces the Okazaki fragments with DNA. B. DNA ligase catalyzes the formation of phosphodiester linkages. C. A different DNA polymerase replaces the RNA primer with DNA. D. DNA polymerase replaces the Okazaki fragments with DNA. E. DNA polymerase synthesizes Okazaki fragments.

C

Classical albinism results from a recessive allele. Which of the following is the expected ratio for the progeny when a normal pigmented male with an albino father has children with an albino woman? A. 3/4 normal, 1/4 albino B. 3/4 albino, 1/4 normal C. 1/2 normal, 1/2 albino D. All normal E. All albino

C

DNA is cut at specific sites by means of A. DNA ligases B. transposons C. restriction enzymes D. DNA slicases E. DNA methylases

C

Density-dependent population growth reflects A. intraspecific mutualism B. interspecific mutualism C. intraspecific competition D. interspecific competition E. intraspecific amensalism

C

Each species has a unique ______ based on where it lives, what it eats, and how it interacts with other species. A. biogeography B. species richness C. niche D. productivity levels E. cascade

C

European settlers brought cattle to Australia. Why did this new cattle industry have problems? A. Native cattle would not interbreed with European cattle. B. European cattle brought diseases that infected native wildlife. C. Native dung beetles would not recycle wet cow manure. D. Native grasses could not support the dietary needs of the European cattle. E. Native predators decimated cattle herds.

C

G. F. Gause experimented with Paramecium interaction between species. If you were to repeat his experiments, growing Paramecium caudatum and Paramecium bursaria together would most likely result in A. no difference than if they were grown apart B. both species going extinct C. both species having lower population growth rates than when grown alone D. both species having higher population growth rates than when grown alone E. oen species always forcing the other into extinction

C

How are inducible and repressible systems similar? A. Both systems control primarily catabolic pathways. B. In both systems, the final product of the pathway usually regulates transcription of the genes that will encode enzymes that produce it. C. In both systems, the regulatory molecules function by binding to the operator D. Blocking transcription is the default state for both systems E. None of the above

C

In a growing DNA strand, each monomer is added to which carbon of the deoxyribose? A. 1' B. 2' C. 3' D. 4' E. 5'

C

In a hypothetical population of sawflies, 20 percent of the population is homozygous for allele A and 45 percent is homozygous for allele a. Assuming that A and a are the only alleles at this locus, what percent of the population is heterozygous? A. 10 percent B. 20 percent C. 35 percent D. 45 percent E. Insufficient information is given to answer the question

C

In a species of tortoise, foot size (big or small) is controlled by one gene, while shell shape (round or lumpy) is controlled by another gene. Suppose that a big-footed lumpy-shelled tortoise mates with a small-footed round-shelled tortoise. Eight offspring result: four big-footed round-shelled tortoises. (Assume that the parents are not necessarily homozygous for each allele.) If big feet (B) in tortoises is dominant to small feet (b), which of the following is the genotype of the big-footed parent with respect to the foot gene? A. bb B. BB C. Bb D. Either bb or BB E. Either bb and Bb

C

In eukaryotes, a promoter is the region of A. a plasmid that binds the enzyme for replication B. the mRNA that binds to a ribosome C. DNA that binds RNA polymerase D. the mRNA that binds tRNAs E. None of the above

C

In terms of increasing complexity, the order of parts in a multicellular organism is A. molecule, tissue, cell, organ, organ system B. tissue, cell, macromolecule, organ system, organ C. molecule, cell, tissue, organ, organ system D. tissue, molecule, cell, organ, organ system E. cell, macromolecule, tissue, organ, organ system

C

In the ABO blood groups in humans, A. A, B, and O are codominant B. A, B, and O are incompletely dominant C. A and B are codominant and are dominant to O D. O is incompletely dominant to A and B E. A is dominant to B and B is dominant to O

C

In the absence of substance of M, a hypothetical LM operon is turned off. If substance M is abundant, it can bind to the repressor, which permits the polymerase to begin transcribing the DNA. In this case, LM is a(n) _____ operon and M acts as a(n) _____. A. repressible, inducer B. repressible, transcription factor C. inducible, inducer D. inducible, co-repressor E. inducible, transcription factor

C

Invasive plant species A. generally provide adaptive disease-inhibiting properties to the native plants B. generally have low growth rates C. are detrimental because they often out-compete native species for resources D. are usually restricted to small areas E. do not pose any threat to native species so long as they are adapted to the area

C

Metsbolism is... A. the consumption of energy B. the release of energy C. all chemical transformations and other work done in a cell or organism D. the production of heat by chemical reactions E. the exchange of nutrients and waste products with the environment

C

Most ATP produced in our bodies is made A. by glycolysis B. in the citric acid cycle C. using ATP synthase D. from photosynthesis E. by burning fat

C

One characteristic of phospholipids that allows them to form a bilayer is their A. hydrophilic fatty acid tail B. hydrophobic head C. hydrophobic fatty acid tail D. hydrophilic glycogen acid tail E. All of the above

C

Paramecium caudatum can exist together with Paramecium bursaria but not with Paramecium aurelia. This is due to A. interspecific competition B. predation C. resource partitioning D. mutualism E. parasitism

C

Plants give off O₂ because A. O₂ results from the incorporation of CO₂ into sugars B. they do no respire; they photosynthesize C. water is the initial electron donor, leaving O₂ as a photosynthetic by-product D. electrons moving down the electron chain bind to water, releasing O₂ E. O₂ is synthesized in the Calvin cycle

C

Put the following four steps of eukaryotic gene expression in order, from beginning to end 1. Pre-mRNA is processed to make mRNA 2. Ribosomes translate the mRNA message to make proteins 3. mRNA is transported to the cytoplasm 4. DNA is used as a template to make pre-mRNA A. 1, 4, 3, 2 B. 4, 3, 1, 2 C. 4, 1, 3, 2 D. 4, 1, 2, 3 E. 1, 2, 4, 3

C

Some proteins that are on the surface of mammalian cells contain carbohydrates. These proteins are synthesized by ______ and the sugars added in the _______. A. mitochondrial ribosomes; smooth endoplasmic reticulum B. cytoplasmic ribosomes; smooth endoplasmic reticulum C. the rough endoplasmic reticulum; Golgi apparatus D. Golgi apparatus; rough endoplasmic reticulum E. cytoplasmic ribosomes; plasma membrane

C

Starch and glycogen, which are both polysaccharides, differ in their functions in that starch is ____, whereas glycogen ____. A. the main component for plant structural support: is an energy source for animals B. a structure material found in plants and animals; forms external skeletons in animals C. the principle energy storage compound of plants: is the main energy storage of animals D. a temporary compound used to store glucose; is a highly stable compound that stores complex liquids E. the main energy storage of animals; is s temporary compound used to store glucose

C

The advantage of controlled experiments is that A. minimal amount of data are required B. the results are predictable C. all variables are held constant except for one D. the hypothesis is proven right E. experiments are conducted in the field, not in a lab

C

The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are A. integral membrane proteins B. carbohydrates C. lipids D. nucleic acids E. peripheral membrane proteins

C

The energy necessary for making a DNA molecule comes directly from A. sugar B. ATP C. the release of extra phosphates from the nucleotides D. NADPH E. NADH

C

The number of individuals of any particular species that can be supported by a particular environment is known as A. exponential growth B. logistic growth C. carrying capacity D. ent reproductive rate E. organismal capacity

C

The organelles and biomolecules present in homogenized cells can be separated by centrifugation. Which of the following would be found at the top of a centrifugation gradient? A. ribosomes B. mitochondria C. ATP molecules D. nuclei E. Golgi

C

The rate at which a substance diffuses is not affected by the A. diameter of the molecules or ions B. temperature of the solution C. color of the substance D. concentration gradient in the system E. Both a and b

C

The ultimate source of energy for ATP synthesis in chloroplasts is A. electron transport B. the electrochemical proton gradient C. light D. energized chlorophylls E. NADPH

C

Transcription factors are A. RNA sequences that bind to RNA polymerase B. DNA sequences that regulate transcription C. proteins that bind to the DNA promoter sequence D> polysaccharides that bind to the transcripts E. factors that bind to enhancers

C

What is the sequence of the complementary strand of DNA given this sequence: 5' AGC TTC GCT GAA GCT 3'? A. 5' TCG AAG CGA CTT CGA 5' B. 5' UCG AAG CGA CUU CGA 3' C. 3' TCG AAG CGA CTT CGA 5' D. 5' GGC TCG AAG TCG CTT 5' E. 3' AGC TTC GCT GAA GCT 5'

C

What was Darwin's explanation for the evolution of bright colors and other apparently useless (and potentially deleterious) but conspicuous characters in males of many species? A. stabilizing selection B. genetic drift C. sexual selection D. disruptive selection E. gene flow

C

When a severely dehydrated patient is brought to the hospital, an IV of normal saline is started immediately. Distilled water is not used because A. it would cause water to leave the cells of the patient and the cells would collapse B. nutrients are provided by the saline C. it would cause the patient's blood cells to swell and eventually burst D. normal saline is more economical E. the distilled water might be contaminated by bacteria

C

Which of the following does not contribute to species composition changes over short periods of time? A. climate change B. colonization C. evolution D. extinction E. disturbance

C

Which of the following events occurs as part of the electron transport chain? A. release of CO₂ B. reduction of CO₂ C. oxidation of FADH and NADH D. reduction of NAD+ E. Both a and b

C

Which of the following evolutionary processes creates new genetic variation? A. natural selection B. genetic drift C. mutation D. both A and B E. both B and C

C

Which of the following initiates the Calvin cycle and results in the entire pathway being carried out under environmental conditions? A. 3GP is reduced to G3P using ATP and NADPH + H protons. B. RuBP is regenerated C. CO2 and RuBP join, forming 3GP D. G3P is converted into glucose and fructose E. Any of the above; since it is a cycle, it can start at any point

C

Which of the following processes increases the genetic diversity of offspring? A. mitosis B. cloning C. sexual reproduction D. cytokinesis E. fission

C

Which of the following represents a correct ordering of the levels of complexity at which life is studied, from most simple to most complex? A. Community, population, organism, organ, tissue, cell B. Cell, organ, tissue, organism, population, community C. Cell, tissue, organ, organism, population, community D. Cell, tissue, organ, population, organism, community E. Tissue, organ, cell, population, organism, community

C

Which of the following statements about X chromosomes inactivation in females is false? A. The probability that a given X chromosome will become inactive is 50 percent. B. Inactivation of the X chromosome seems to involve methylation of cytosine on DNA. C. The Barr body is a clump of euchromatin representing the inactivated X chromosome. D. An abnormal male with the genotype XXY would have one Barr body.

C

Which of the following statements about the nucleus in animal cells is false? A. DNA replication takes place in the nucleus. B. The nucleus occupies the largest volume of the cell. C. The nucleus is the site of protein synthesis. D. DNA is the nucleus combines with proteins. E. The nucleolus is located in the nucleus.

C

Explain the role of catabolic and anabolic pathways in cellular respiration.

Catabolic pathways release the energy stored in complex molecules through the breakdown of these molecules into simpler compounds. Anabolic pathways, sometimes called biosynthetic pathways, require energy to combine simpler molecules into more complicated ones.

Cell Wall Plasma Membrane Bacterial Chromosome Nucleoid Cytoplasm Flagella

Cell Wall- rigid structure outside the plasma membrane. Plasma Membrane- membrane enclosing the protiens. Bacterial Chromosome- Chromosome is bacteria Nucleoid- Region where the cell's DNA is located (not enclosed by membrane. Cytoplasm- Region between the nucleus and the plama membrane of a eukaryotic cell. Flagella- Locomotion organelles of some bacteria

Pinocytosis

Cell drinking. Examples are the uptake of solutes in fluids.

Phagocytosis

Cell eating. Examples are carbohydrates.

Exocytosis

Cell secretes molecules. Examples are enzymes, such as salivary amylase.

Endocytosis

Cell takes in biological molecules. Examples are ingested bacteria, such as salmonella.

Why don't plant cells burst?

Cell walls.

Why are cells so small? Explain the relationship of surface area to volume.

Cells are so small because if a cell grows beyond a certain limit, not enough material will be able to cross the cell membrane. As a cell increases in size the volume grows proportianately more than its surface area. (Area is proportional to a linear dimension squared, whereas volume is proportional to the linear dimension cubed)

Cilia vs. Flagella

Cilia- occur in large number, differ in beating pattern (oars) Flagella- one or few

Electrochemical Gradient

Combination of chemical force and electrical force on an ion.

Peroxisomes

Contain enzymes that transfer hydrogen from various substrates to oxygen, producing peroxide.

Intracellular receptors are found in the ______ or ______ of the cell, where they bond to chemical messengers that are _____ or very small, like nitric acid.

Cytoplasm... nucleus... hydrophobic

A bacterial cell gives rise to two genetically identical daughter cells by a process known as A. nondisjunction B. mitosis C. meiosis D. binary fission E. fertilization

D

A bee visits a flower, picking up pollen that it transfer to the next flower it visits. This is an example of A. predation B. parasitism C. altruism D. mutualism E. herbiovory

D

A cell A. is always prokaryotic B. is never an entire organism C. is found only in plants and animals D. is the fundamental unit of life E. always contains a nucleus

D

A community differs from a population in that a community A. consists of just one species B. is a group of the same species that interact with each other C. includes the abiotic environment D. consists of many species E. is synonymous with an ecosystem

D

A group of species that coexist and interact with one another in a defined geographic area constitute a(n) A. symbiosis B. population C. food web D. community E. ecosystem

D

A life table is used for A. recording the life history of an individual in a population B. determining the survivorship for individuals in a population C. estimating population densities D. displaying information about birth and death rates in a population E. understanding dispersion patterns in a population

D

A newly-discovered organism lives in acidic pools in volcanic craters where temperatures often reach 100°C and normally stay above 90°C. It has a surface enzyme that catalyzes a reaction leading to its protective coating. At which temperature would you most likely find optimal activity of this enzyme? A. 0°C B. 37°C C. 55°C D. 95°C E. 105°C

D

A phospholipid differs from a triglyceride in that phospholipids A. are used to store energy in the cell B. are not derivatives of glycerol C. do not have both hydrophilic and hydrophobic parts D. are amphipathic E. do not contain fatty acids

D

A reaction that has a negative ∆G A. necessarily proceeds more rapidly than a reaction with a less negative ∆G B. is always paired with a reaction with a positive ∆G C. is endergonic D. is spontaneous E. cannot be used to drive a reaction with a positive ∆G

D

Although the consequences of various kinds of disturbances are highly variable, their results conform to a general pattern. This general pattern is called A. intermediate equilibrium B. disaster equilibrium C. general disturbance D. succession E. general equilibrium

D

Amoeba proteus is injected with a drug that inhibits the formation of microtubules. What effects does this have on the organism's movement? A. It only moves in one direction. B. It dies. C. It shows hyperactive movement. D. It continues to move with no effect. E. It is alive but rounds up and does not move.

D

An ecologist measures off a transect running through a park and identifies and plants at regular intervals. THe transect passes through various types of soils. As she moves through the transect she observes that some plants drop out as new ones appear. This pattern is called A. colonization B. succession C. mutualism D. species turnover E. interspecific competition

D

As an ecologist you compare three communities, which are listed below. Which community has the highest species diversity? Community 1 = 3 equally abundant species Community 2 = uneven distribution of 4 species Community 3 = 4 equally abundant species A. Community 1 B. Community 2 C. Community 3 D. Communities 2 and 3 are equal. E. All communities are equal.

D

Biologists have organized the diversity of life into three domains based largely on A. physical similarities B. ecological niches C. chronological order D. molecular data E. All of the above

D

Chromatin condenses to form discrete, visible chromosomes A. early in G1 B. during S C. during telophase D. during prophase E. at the end of cytokinesis

D

DNA acetylation A. promotes transcription in operons B. loosens the DNA so RNA polymerase can access it C. adds acetyl groups to DNA to block transcription D. A and B

D

During cyclic electron transport, the energy to produce ATP is provided by A. heat B. NADPH C. ground-state chlorophyll D. the redox reactions of the electron transport chain E. the Calvin cycle

D

Entropy A. when multiplied times the absolute temperature, is the useable energy in a system B. is the total energy in a system C. is represented in equations by the letter "H" D. is related to the disorder or randomness of a system E. tends to decrease the total energy in the universe

D

Food webs are representations of ______ in a community. A. the detritivores that recycle nutrients B. how species are related C. all of the primary consumers D. the trophic interactions E. the amount of biomass

D

For each molecule of ATP consumed during active transport of sodium and potassium, there is an import of ____ ion(s) and an export of ____ ion(s). A. two Na+; three K+ B. two Na+; one K+ C. one K+; three Na+ D. two K+; three Na+ E. three K+; two Na+

D

If glucose and lactose are both abundant, would it be beneficial for E coli cells to express the genes that metabolize lactose? Why or why not? A. Yes, bacteria require both glucose and lactose B. Yes, it is easier for bacteria to metabolize lactose than glucose C. Yes, three proteins are required for the uptake and metabolism of lactose. D. No, lactose is broken down into glucose. E. No, lactose metabolism requires an inducer.

D

In the scientific method, a hypothesis A. is a final answer to a question B. is formulated by deductive logic C. does not have to be testable D. is the basis for making predictions E. is formulated solely by speculation

D

In tomatoes, tall is dominant to short and smooth fruits are dominant to hairy fruits. A plant that is homozygous for both dominant traits is crossed with a plant that is homozygous for both recessive traits. The F1 progeny are tested and crossed with the following results: 78 tall, smooth fruits; 82 short, hairy fruits; 22 tall, hairy fruits, and 18 short, smooth fruits. This data indicates that the genes are A. on different chromosomes B. linked, but do not cross over C. linked and show 10 percent recombination D. linked and show 20 percent recombination E. linked and show 40 percent recombination

D

Interphase involves all of the following except A. DNA replication B. the synthesis of cellular components necessary for mitosis C. G1 D. the condensation of chromatin E. G2

D

Populations or organisms have been able to inhabit a wide variety of environments on Earth because they have A. have a genome B. contain organelles C. carry out photosynthesis D. adapt through evolution E. are similar to model organisms

D

Predation is the type of interaction in which A. two organisms use the same limited resources B. one participant benefits and the other is unaffected C. one participant is harmed but the other is unaffected D. one participant is harmed while the other benefits E. both participants benefit

D

Prokaryotes A. have a cell wall similar in composition to that of plant cells B. do not have ribosomes C. are larger than eukaryotic cells D. are surrounded by a plasma membrane E. have a nucleus

D

RNA polymerase uses the _____ DNA template to synthesize a _____ mRNA. A. 5' to 3'; 5' to 3' B. 3' to 5'; 3' to 5' C. 5' to 3'; 3' to 5' D. 3' to 5'; 5' to 3' E. Examples of all of the above have been found

D

Species introduced to regions outside their original range that then spread widely and become abundant at a cost to the native species of the region are known as ______ species. A. fragmented B. endemic C. parasitic D. invasive E. exotic

D

The _____ region of a phospholipid forms the ____ of a cell membrane and the ____ region would form the ____. A. hydrophobic; interior; hydrophilic; surface B. hydrophobic; surface; hydrophilic; interior C. hydrophobic; surface; hydrophobic; surface D. hydrophilic; surface; hydrophobic; interior E. hydrophilic; inteior; hydrophobic; interior

D

The chemiosmotic generation of ATP is driven by A. osmotic movement of water into an area of high solute concentration B. the addition of protons to ADP and phosphate via enzymes C. oxidative phosphorylation D. the proton motive force E. isocitrate dehydrogenase

D

The difference between osmosis and diffusion is that A. diffusion is passive transport, whereas osmosis is active transport B. only in diffusion do molecules move from areas of high concentration to areas of low concentration C. only diffusion refers to the movement of materials across a semipermeable membrane D. osmosis refers specifically to the movement of water, whereas diffusion refers to the movement of any type of molecules E. the process of osmosis varies according to the kinds of particles present

D

The endomembrane system A. functions to make ATP. B. is present in prokaryotes. C. includes the endoplasmic reticulum and the mitchondria. D. includes the Golgi apparatus and the endoplasmic reticulum. E. does not exist in plant cells.

D

The one major dip in human ppopulation growth that occured from 1340-1355 was caused by A. tuberculosis B. malaria C. the "Green Revolution" D. bubonic plague E. All of the above

D

The particular allele of a gene that is present in most individuals in nature is referred to as A. dominant B. recessive C. epistatic D. wild type E. polymorphic

D

The primary structure of proteins is the ____. The primary structure contains the information necessary for the formation of secondarys tructure, including the ____ and the ____. Secondary structure of proteins is stabilized by the formation of ____ bonds. A. amino acid sequence; β pleated sheet; α helix; disulfide B. α helix; amino acid sequence; β pleated sheet; hydrophobic C. amino acid sequence; α helix; β pleated sheet; peptide D. amino acid sequence; α helix; β pleated sheet; hydrogen E. β pleated sheet; α helix; smino acid sequence; hydrogen

D

The proteins that make up the cytoskeleton of bacteria are similar to _______ in eukaryotic cells. A. sterols B. telomerases C. transcription factors D. actin E. proteases

D

The reactivity of an atom arises primarily from the A. average distance of the outermost shell from their nucleus B. sum of the potential energies of all electron shells C. energy difference between the electron shells D. existence of unpaired electrons in the outermost shell E. potential energy of the outermost

D

The role of oxygen gas in our cells is to A. catalyze reactions in glycolysis B. produce CO2 C. form ATP D. accept electrons from the ETC and protons from the gradient E. react with glucose to split water

D

The size of horns in males of a particular beetle have an interesting distribution: the highest frequencies are around 15 millimeters and 30 millimeters, with few individuals in between. Based on this observation, which of the following modes of selection is most likely to be operating on these horns. A. stabilizing selection B. directional selection C. concentrated selection D. disruptive selection E. purifying selection

D

The species that live and interact in an area constitute a(n) A. ecosystem B. biome C. lek D. ecological community E. population

D

The water that is a by-product of cellular respiration is produced as a result of the A. combining of carbon dioxide with protons B. conversion of pyruvate to acetyl CoA C. degradation of glucose to pyruvate D. reduction of oxygen at the end of the electron transport chain E. None of the above

D

UGU and UGC both code for cysteine. A change from UGU to UGC would thus be a _____ mutation. A. missense B. nonsense C. ambiguous D. silent E. None of the above

D

Which of the following is not a polymer? A. A protein B. A nucleic acid, such as DNA C. A polysaccharide carboyhydrate D. A lipid E. All of the above are polymers

D

Which of the following statements about infection of E coli cells by bacteriophage T2 is true? A. Proteins are the only phage components that enter the infected cell. B. Both proteins and nucleic acids enter the cell. C. Only protein from the infecting phage can be detected in progeny phage. D. Only nucleic acids enter the cell. E. More than one phage particle is required to produce infection.

D

Which of the following statements about osmosis is false? A. Osmosis refers to the movement of water along a concentration gradient. B. In osmosis, water moves to equalize solute concentrations on either side of the membrane. C. The movement of water across a membrane can affect the turgor pressure of some cells. D. If osmosis occurs across a membrane, then diffusion is not occurring. E. During osmosis, water is moving through membrane channels.

D

Which of the following statements about the flow of genetic information is true? A. Proteins encode information that is used to produce other proteins of the same amino acid sequence. B. RNA encodes information that is translated into DNA, and DNA encodes information that is translated into proteins. C. Proteins encode information that can be translated into RNA, and RNA encodes information that can be transcribed into DNA. D. DNA encodes information that is translated into RNA, and RNA encodes information that is translated into proteins. E. None of the above

D

Which of the following tends to reduce genetic variation within populations? A. genetic drift B. stabilizing selection C. directional selection D. All of the above E. None of the above

D

You are experimenting with sunflower photosynthetic rates. You expose different plants to different light intensities ranging from no light to full sun. What type of relationship do you expect to see between increasing light intensity and the rate of photosynthesis? A. The rate of photosynthesis increases with no limit. B. The rate of photosynthesis is equal at all light levels. C. The rate of photosynthesis decreases with no limit. D. The rate of photosynthesis decreases, but eventually levels off. E. The rate of photosynthesis increases, but eventually levels off.

D

_______ is/are divisions of organisms in a community based on feeding position. A. Consumers B. Food webs C. Pyramids D. Trophic levels E. A food chain

D

A plant species produces a chemical that is toxic to herbivores. Over time, herbivores that can detoxify the chemical increase in frequency. A mutation in the plant produces a new, different toxic chemical that the herbivores cannot detoxify. This is an example of A. resource partitioning B. mutualism C. amensalism D. commensalism E. evolutionary arms race

E

Biological membranes are composed of A. nucleotides and nucleotides B. enzymes, electron acceptors, and electron donors C. fatty acids D. monosaccharides E. lipids, proteins, and carbohydrates

E

Cilia and eukaryotic flagella A. propel cells by rotation of the structures B. contain microtubules that are sufficient to drive movement C. contain microfilaments D. contain centrioles E. must have a motor protein that uses the energy of ATP hydrolysis to power movement

E

Commensalism is the type of interaction in which A. both participants benefit B. two organisms use the same limited resources C. one participant is harmed but the other is unaffected D. one participant is harmed while the other benefits E. one participant benefits and the other is unaffected

E

Covalent bond formation depends on the ability of atoms to A. share electrons with other atoms B. donate electrons to the other atoms C. receive electrons from other atoms D. both a and b E. all of the above

E

DNA strands can be visualized using which of the following instruments? A. light microscopes B. dissecting microscope C. centrifuge D. thermocycler E. electron microscope

E

DNA, because it has a ____ charge, moves to the ____ end of the field in gel electrophoresis; _____ DNA molecules migrate the most quickly. A. positive, positive, smaller B. positive, positive, larger C. positive, negative, smaller D. negative, positive, larger E. negative, positive, smaller

E

Distribution of ages in a population can be determined by A. rate of population growth B. timing of deaths C. timing of births D. both b and c E. All of the above.

E

Earth is approximately ______ years old. A. 1,000 - 2,000 B. 4,000 - 5,000 C. 4 - 5 million D. 1 - 2 billion E. 4 - 5 billion

E

Fatty acids are A. large polymers of monosaccharides B. linked to glycerol in fats by hydrogen bonds C. water soluble D. always saturated E. carboxylic acids with long hydrocarbon tails

E

Genetic mutations are A. rare B. stable C. inherited changes in DNA D. the process by which all alleles can change to become different alleles E. All of the above

E

If a red blood cell is placed in an isotonic solution, it will A. shrivel B. swell and burst C. shrivel and then return to normal D. swell and then return to normal E. take up and release water at equal rates

E

If samples were brought back from a distant planet, what would be the first evidence of life, assuming its evolution followed the same path as earth? A. presence of fatty acids B. cell membranes C. multicellular life forms D. oxygen detected E. presence of nucleic acids

E

Imagine that there is a mutation in the cyclin gene such that its gene product is nonfunctional. What kind of effect would this mutation have on a skin cell in the area of a cut? A. CdK would not be synthesized. B. There would be no effect because skin cells do not replicate. C. The cell would be stuck in S phase and unable to replicate. D. The cell would not be able to enter G1. E. The cell would be unable to reproduce itself.

E

In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short plants, and the F1 plants, which are tall, are allowed to self-pollinate. What fraction of the F2 generation are both tall and heterozygous? A. 1/8 B. 1.4 C. 1/3 D. 2/3 E. 1/2

E

In a species of tortoise, foot size (big or small) is controlled by one gene, while shell shape (round or lumpy) is controlled by another gene. Suppose that a big-footed lumpy-shelled tortoise mates with a small-footed round-shelled tortoise. Eight offspring result: four big-footed round-shelled tortoises. (Assume that the parents are not necessarily homozygous for each allele.) Which statement about the inheritance of footedness in tortoises is most likely to be correct, given your genetic analysis of the tortoise family. A. Big is dominant to small. B. Small is dominant to big. C. Big and small are codominant. D. Both A and C. E. This cannot be answered without more information.

E

In addition to the bilayer of lipids and proteins, membranes may contain _____ in the form of _____ and _____. A. nucleic acids; DNA; RNA B. carbohydrates; cellulose; starch C. triglycerides; fats; oils D. nucleotides; ATP; GTP E. carbohydrates; glycoproteins; glycolipids

E

In cocker spaniels, black color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s). If the genes are unlinked and the offspring of BBss and bbss individuals are mated with each other, what fraction of the next generation will be black and spotted? A. 1/16 B. 9/16 C. 1/9 D. 3/16 E. 3/4

E

In the Krebs cycle, oxidative steps are coupled to A. oxidative phosphorylation B. the oxidation of water C. the oxidation of hydrogen carriers D. the hydrolysis of ATP E. the reduction of hydrogen carriers

E

Liver cells are exposed to radioactive amino acids; all proteins synthesized during this time are radioactive. The cells are then removed at 5-minute intervals and fractionated. Where in the cells is the radioactively labeled enzyme lipase performing its intracellular functions? A. in the endoplasmic reticulum B. on ribosomes C. in the cytoskeleton D. in the Golgi E. in lysosomes

E

Mutualism is the type of interaction which A. one participant is harmed while the other benefits B. one participant is harmed but the other is unaffected C. one participant benefits and the other is unaffected D. two organisms use the same limited resources E. both participants benefit

E

Nucleic acids are not found in which of the following structures? A. mitochondria B. the nucleus C. prokaryotic cells D. ribosomes E. plant vacuoles

E

Phosphorylation of ADP to ATP is endergonic, whereas the hydrolysis of ATP to ADP is exergonic. The two reactions are therefore said to be A. substrates B. endergonic C. kinetic D. activated E. coupled

E

Photosynthesis was a major evolutionary milestone because A. photosynthetic organisms contributed oxygen to the environment, which led to the evolution of aerobic organisms B. photosynthesis led to conditions that allowed life to arise on land C. photosynthesis is the only metabolic process that can convert light energy to chemical energy D. photosynthesis provides food for organisms E. All of the above

E

Plants are ____ organisms that are ____ of oxygen production. A. eukaryotic unicellular; capable B. eukaryotic multicellular; incapable C. prokaryotic multicellular; capable D. prokaryotic unicellular; incapable E. eukaryotic multicellular; capable

E

Plants show remarkable diversity, even though they were derived from a common ancestor. Which of the following is not a contributing factor to this diversity? A. genetic drift B. natural selection C. sexual selection D. structural adaptions E. All of the above contributed to this diversity

E

Populations stop growing exponentially because A. birth rates decrease. B. death rates increase. C. they reach carrying capacity. D. the per capita growth rate = 0 E. All of the above

E

The Calvin cycle uses _____ to produce glucose. A. CO₂ B. ATP C. NADPH D. rubisco E. All of the above

E

The basic steuctural and physiological unit of all living organisms is the A. aggregate B. organelle C. organism D. membrane E. cell

E

The energy to move chromosomes during mitosis is provided by A. centrioles B. DNA polymerization C. migration of the centrosomes D. formation of the cell plate E. ATP

E

The extracellular matrix of animal cells A. is involved in chemical signaling between cells. B. helps filter materials passing between tissues. C. contains proteoglycans. D. contains collagen. E. all of the above.

E

The interaction between some fungi and leaf-cutter ants that farm them is best described as A. amensalism B. predation C. commensalism D. competition E. mutualism

E

The organisms that produced the oxygen gas in Earth's atmosphere paved the way for the type of metabolism in a larger organisms, called _______ metabolism. A. photosynthetic B. anaerobic C. heterotrophic D. is the basis for making predictions E. is formulated solely by speculation

E

The products of mitosis are A. one nucleus containing twice as much DNA as the parent nucleus B. two genetically identical nuclei C. four nuclei containing half as much DNA as the parent nucleus D. four genetically identical nuclei E. two genetically identical nuclei

E

The regulation of biochemical pathways in cells often occurs by ____ mechsnisms, with the end product of the pathway actings as a(n) ____ of the enzyme that catalyzes the first step of the pathway. A. irreversible; dead-end inhibitor B. allosteric; competitive inhibitor C. competitive; competitive inhibitor D. allosteric; activator E. allosteric; noncompetitive inhibitor

E

The synthesis of complex molecules _______ energy, whereas the degradation _______ energy. Synthesis occurs with _______ in entropy. A. requires; releases; no change B. releases; requires; an increase C. requires; releases; a decrease D. releases; requires; no change E. requires; releases; an increase

E

Water is essential to life. Which of the following physical properties of water affect(s) life in some beneficial way? A. cohesiveness B. high heat capacity C. high heat of vaporization D. hydrogen bonds E. all of the above

E

What is required for natural selection to occur? A. Organisms must display variation. B. A trait must be able to be passed on to future generations. C. A trait must increase survival. D. A trait must increase reproduction. E. All of the above.

E

Which of the following are not involved in the process of transcription? A. RNA polymerase B. transcription factors C. promoters D. TATA box E. ribosomes

E

Which of the following biological groups is dependent on photosynthesis for its survival? A. vertebrates B. mammalia C. fishes D. plants E. All of the above

E

Which of the following biological molecules are linked by covalent bonds formed by the removal of the elements of water from the reactants (a kind of condensation reaction)? A. oils B. fats C. proteins D. starch E. all of the above

E

Which of the following enzymes would be used to join two DNA fragments? A. reverse transcriptase B. DNA polymerase C. DNA recombinase D. DNA endonuclease E. DNA ligase

E

Which of the following is not a potential point of regulation of gene expression? A. The level of transcription B. The level of processing mRNA C. The level of mRNA stability D. The level of translation E. All of the above are potential points of gene regulation

E

Which of the following is not an example of succession? A. A pond changing to a meadow. B. Forest being clear-cut C. Shrubs filling in a forest gap D. The recolonization of Mount St. Helens after its eruption E. The self-perpetuation of a climax community

E

Which of the following statements about prokaryotes is true? A. They generally live in static environments. B. The most efficient means of regulation of gene expression in these organisms is usually at the level of transcription. C. By making certain proteins only when needed, they save energy and other resources. D. Both A and B E. Both B and C

E

Which of the following statements about protein segments is true? A. The structure is an example of tertiary structure. B. The structure is maintained by hydrogen bonding between amino acid side chains. C. Disulfide bridges and ionic interactions help maintain the structure. D. The type of structure shown always involves polypeptides. E. A protein's primary structure determines whether or not the structure shown will form.

E

You are working on a research paper analyzing fossilized remains of plants. You determine when they were alive by using carbon-14 dating. This technique will help you reconstruct A. the evolution of new rat species B. natural selection for cold-adapted species C. the rise of the gymnosperms D. plate tectonics E. the change in plant communities as climate change

E

Protein phosphatases

Enzymes that remove phosphate groups from proteins. They help to rapidly turn off a signal-transduction pathway, then the initial signal is no longer present.

Describe the difference between the location of DNA in prokaryotic and eukaryotic cells?

Eukaryotic- DNA is in an organelle called the nucleus, which is bounded by double membrane. Prokaryotic- DNA is in concentrated in a non membrane enclosed nucleoid.

Distinguish between exergonic and endergonic reactions i terms of free energy change.

Exergonic reaction proceeds with a net release of free energy and is spontaneous. Endergonic reactions are nonspontaneous; they must absorb free energy from the surroundings

Give me an example of a cotransporter in action.

For example, a plant cell uses the gradient of H+ generated by its proton pumps to drive the active transport of amino acids, sugars, and several other nutrients into the cell. One transport protein couples the return of H+ to the transport of sucrose into the cell. (Figure 7.21) This protein can translocate sucrose into the cell against its concentration gradient (more sugar inside the cell than outside), but only if the sucrose molecule travels in the company of a hydrogen ion. The hydrogen ion uses the transport protein as an avenue to diffuse down the electrochemical gradient maintained by the proton pump. Plants use sucrose-H+ cotransport to load sucrose produced by photosynthesis into cells in the veins of leaves. The vascular tissue of the plant can then distribute the sugar to nonphotosynthetic organs, such as roots.

Type of Ribosome Location Product Free Ribosomes Bound Ribosomes

Free Ribosomes - Location- Suspended in Cytosol. - Product- Enzymes Bound Ribosomes - Location- Attached to the outside of the endoplasmic reticulum or nuclear envelope. - Product- Lysosomes

Understand the elements of a reaction diagram

Free energy (x) & Course of Reaction (y): substrate, transition state, activation energy, change in energy between substrate and product, & product

Explain the mechanism of disease in cholera.

G protein cannot hydrolyze GTP to GDP enzyme that the G protein activates is always on cAMP constantly is being produced salt is constantly released as a cellular response due to osmosis, diarrhea.

Enzymes are globular proteins that exhibit at least tertiary structure. As you study Figure 5.20 in your text, use this figure to identify and explain each interaction that folds this protein fragment. -Look at diagram from question 47

Hydrophobic interaction: amino acids with hydrophobic R groups end up in clusters at the core of the protein, out of contact with water. Van der Waals interaction: transient interactions between R groups Hydrogen Bond: weak bonds between the hydrogen of one R group and the oxygen or nitrogen of another R group Disulfide Bridge: links between the sulfhydryl groups of two cysteine amino acids, sulfur to sulfur Ionic Bond: bonds between an R group that is positively charged and an R group that is negatively charged These interactions tend to fold an amino acid chain into a distinctive three-dimensional form. *LOOK AT DIAGRAM TO FOR EACH STEP*

How does the concept of passive transport change in the case of ions.

In the case of ions, we must refine our concept of passive transport: An ion diffuses not simply down its concentration gradient but, more exactly, down its electrochemical gradient. For example, the concentration of Na+ inside a resting nerve cell is much lower than outside it. When the cell is stimulated, gated channels open that facilitate Na+ diffusion. Sodium ions then "fall" down their electrochemical gradient, driven by the concentration gradient of Na+ and by the attraction of these cations to the negative side (inside) of the membrane. In this example, both electrical and chemical contributions to the electrochemical gradient act in the same direction across the membrane, but this is not always so. In cases where electrical forces due to the membrane potential oppose the simple diffusion of an ion down its concentration gradient, active transport may be necessary. In Chapter 48, you will learn about the importance of electrochemical gradients and membrane potentials in the transmission of nerve impulses.

What is cotransport?

It is a single ATP-powered pump that transports a specific solute that can indirectly drive the active transport of several other solutes in a mechanism. The substance that has been pumped across a membrane can do work as it moves across the membrane by diffusion, analogous to water that has been pumped uphill and performs work as it flows back down. Another transport protein, a cotransporter separate from the pump, can couple the "downhill" diffusion of this substance to the "uphill" transport of a second substance against its own concentration gradient (or electrochemical) gradient.

What is an electrogenic pump?

It is a transport protein that generates voltage across a membrane. The sodium-potassium pump appears to be the major electrogenic pump of animal cells. The main electrogenic pump of plants, fungi, and bacteria is a proton pump, which actively transports protons (hydrogen ions, H+) out of the cell. The pumping of H+ transfers positive charge from the cytoplasm to the extracellular solution. By generating voltage across membranes, electrogenic pumps help store energy that can be tapped for cellular work. One important use of proton gradients in the cell is for ATP synthesis during cellular respiration (CR).

What would happen in a hypotheical cell with membrane permeable only to K+?

K+ diffues out of the cell until chemical force due to concentration gradient is opposed by sufficient electtrical focre due to the membrane potential to prevent any more net diffusion. This value of electrical force is called Nernst potential for potassium or the equilibrium potential for potassium.

Integral Membrane Protein

Make sure you know which region is the hydrophilic region, hydrophobic region. Here you can see the alpha-helical configuration. In these two proteins, the left side is a single pass protein and the right side protein is a multi-pass protein. Integral proteins are mainly found either fully or partially submerged in the phospholipids bilayer of the plasma membrane. These proteins have both polar and non-polar regions on them. Polar heads protrude from the surface of the bilayer while non-polar regions are embedded in it. Usually only the non-polar regions interact with the hydrophobic core of the plasma membrane by making hydrophobic bonds with the fatty acid tails of the phospholipids. The integral proteins that span the entire membrane from the inner surface to the outer surface are called transmembrane proteins. In transmembrane proteins, both ends that project out of the lipid layer are polar or hydrophilic regions. The middle regions are non-polar and have hydrophobic amino acids on their surface

At cells resting potential is the cell at equilibrium?

NO steady state bc K is leaking out and na is leaking in this leakage is exactly balanced by the Na K pump which pump Na out and K in the metabolic energy is necessary to maintain ion gradients

What would happen in a hypothetical cell with membrane permebale only to Na+?

Na+ diffuses into the cell until the chemical foce due the concentration gradient is opposed by sufficeinet electrical force due to the membrane potential to proevent any more net diffusion. This is the value of electircal force is called Nernst potnetial for sodium or equilibrium potneial for sodium.

What is the nuclear lamina? Nuclear matrix?

Nuclear Lamina- a netlike array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope. Nuclear matrix- a framework of fiber extending throughout the nuclear interior.

The large molecules of all living things fall into just four main classes. Name them.

Proteins, lipids, carbohydrates, and nucleic acids

5 Forms of Active Transport

Proton Pump Sodium Potassium Pump Phagocytosis Pinocytosis Receptor mediated endocytosis

What is the function of ribosomes? What are their two components?

Ribosomes- complexes made of ribosmal RNA abd protein, are the cellular components and carry out protein synthesis. The two components are Ribosmal RNA and proteins.

What activates a G protein?

Signaling protein activates receptor receptor changes shape G protein binds to enzyme.

Besides packaging secretory proteins into transport vesicles, what is another major function of the rough ER?

The membrane keeps them separate from proteins that are produced by free ribosomes and will remain in the cytosol. Rough ER is a membrane factory for the cell; it grows in place by adding membrane proteins and phospholipids to its own membrane.

How does the membrane potential act like a battery?

The membrane potential acts like a battery, an energy source that affects the traffic of all charged substances across the membrane. Because the inside of the cell is negative compared with the outside, the membrane potential favors the passive transport of cations into the cell and anions out of the cell. Thus, two forces drive the diffusion of ions across a membrane: a chemical force (the ion's concentration gradient) and an electrical force (the effect of the membrane potential on the ion's movement). This combination of forces acting on an ion is called the electrochemical gradient.

How does active transport work?

To pump a solute across a membrane against its gradient require work; the cell must expend energy. Therefore, this type of membrane traffic is called active transport. The transport proteins that move solutes against their concentration gradients are all carrier proteins rather than channel proteins. This makes sense because when channel proteins are open, they merely allow solutes to diffuse down their concentration gradients rather than picking them up and transporting them against their gradients. Active transport enables a cell to maintain internal concentrations of small solutes that differ from concentrations in its environment. For example, compared with it surroundings, an animal cell has a much higher concentration of potassium (K+) and a much lower concentration of sodium ions (Na+). The plasma membrane helps maintain these steep gradients by pumping Na+ out of the cell and K+ into the cell.

Here is a molecule of starch, which shows 1-4 glycosidic linkages. Translate and explain this terminology in terms of carbon numbering.

When glucose forms a ring, the hydroxyl group attached to the number 1 carbon is positioned either below or above the plane of the ring. These two ring forms for glucose are called alpha and beta. In starch, all the glucose monomers are in the alpha configuration.

Do cells have voltages across their membranes?

Yes, all cells have voltages across their plasma membranes. Voltage is electrical potential energy - separation of opposite charges. The cytoplasmic side of the membrane is negative in charge relative to the extracellular side because of an unequal distribution of anions and cations on the two sides. The voltage across a membrane, called a membrane potential, ranges from about -50 to -200 millivolts (mV). (The minus sign indicates that the inside of the cell is negative relative to the outside.

Polygenic Trait

a characteristic of an organism that is determined by many genes

Define concentration gradient

a difference in concentration of a substance from one location to another, often across a membbrane

meiosis

a process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells

Karyotype

an array of the chromosomes found in an individual's cells at metaphase of mitosisan arranged in homologous pairs and in order of diminishing size

*Know how to identify the four different types of protein structures* -Label diagram from question 46

answers found on diagram from question 46 (primary- line, secondary- folds or coils, tertiary- chunk, Quaternary- multiple chunks)

Autosome

any chromosome that is not a sex chromosome

homologous chromosome

chromosomes that have the same sequence of genes, that have the same structure, and that pair during meiosis

Homologous Chromosome

chromosomes that have the same sequence of genes, that have the same structure,and that pair during meiosis

How do the follow cross the membrane: - CO2 - Glucose - O2 - H2O

co2 - simple diffusion (passive ) from high concentration to low concentration regions glucose - active transport of ions to form a gradient. glucose transport is coupled with the ions movement down the concentration gradient (i.e. Na+ moves back from outside the cell where there is a high concentration of Na+ and takes with it glucose). An example of symport transport O2 - simple diffusion (passive) from high concentration to low cconcentration regions Osmosis (passive) of water from areas of low solute concentration to high solute concentration or high water potential to low water potential or from pure water to less pure water

Describe how each of the following can affect membrane fluidity - decreasing temperature - phospholipids with unsaturated hydrocarbon chains - cholesterol

decreasing temperature - decreases fluidity by causing membrane to "freeze." phospholipids with unsaturated hydrocarbon chains - increases fluidity because "kinks" prevent packing in of molecules cholesterol - increases fluidity when cold & decreases fluidity when hot. Cholesterol acts as a buffer,

Heterozygous

describes an individual that has 2 different alleles for a trait

zygote

diploid cell formed when the nucleus of a haploid sperm cell fuses with the nucleus of a haploid egg cell

What is the chemical force?

force only due to the chemical concentration gradient-it makes it move from an area of high con to an area of low conc neither the sign of the ion nor the strength of the membrane potential affect the direction or size of the chemical force.

Name the correct carbohydrate for each? Monosaccharide commonly called "fruit sugar"

fructose

Describe conductance. What happens to the membrane potential if Conducance is increased?

g Reciprocoal of resistance Term used in the Equivalent Circuit Model of the electrical properties of the cell membrane. As the relative conductance of ion increases the membrane potential moves closer to the Nerst potential of that ion

The root words of hydrolysis will be used many times to form other words you will learn this year. What does each root word mean? -hydro: -lysis

hydro- water lysis- break

What is the ionization constant for NACL --> Na+ + CL-

i=2

What is the ionization constant for MgCl2 MgCl2--> Mg2+ + 2Cl-

i=3

Membrane proteins are the mosaic part of the model. Describe each of the two main categories: - integral proteins - peripheral proteins

integral proteins - proteins embedded in the membrane that protrude through to the interior and exterior peripheral proteins - proteins associated with the surface of the membrane. Some act as identification proteins (MHC), others act as receptor proteins.

How is the fluidity of cell membrane's maintained?

movement of phospholipids- lipids move laterally within the rapid membrane. Membrane fludity- unsaturated hydrocarbons have kinked tails so they don't perk together. Cholesterol- Reduces fluidity at moderate temps, hinders solidification at low temps.