Exam 2 Biology Sapling

the conversion of pyruvate to acetyl CoA

Mitochondrial matrix

M

Mitosis occurs

Why does disruption of oxidative phosphorylation also disrupt other cellular processes?

Oxidative phosphorylation generates ATP, which is required for many cellular processes.

The process of meiosis is responsible for creating much of the genetic variation seen in sexually reproducing organisms. Which events in the process of meiosis generate this genetic variability?

-A homologous pair lines up along the metaphase plate independently of the other pairs. -The arms of adjacent chromatids cross over and switch places with each other in prophase I.

When a person is sprinting, the person\'s muscle cells will begin using anaerobic respiration in addition to keeping the mitochondria respiring aerobically as much as the oxygen supply will allow. What benefits do muscle cells gain from anaerobic respiration in this situation?

-Without using oxygen, the cell generates two ATP molecules that can keep the muscles moving for every glucose molecule that enters glycolysis. -Adding electrons from NADH to pyruvate regenerates NAD , so that glycolysis can continue, and produces lactic acid, a waste product that can diffuse out of the cell.

the cells produced by meiosis 2 in this animal have a __1__ chromosome number and are produced after __2__ have pulled apart into seperate daughter cells.

1. Haploid 2. Sister chromatids

the cells produced by meiosis 1 in this panda have a __1___ chromosome number and are produced after __2___ have been pulled apart into spereate daughter cells.

1. Haploid 2.Homologous chromosomes

Germ cells within the animals testicles undergo ___1____ to replicate themselves and ____2___ to produce sperm

1. mitosis 2. Meiosis

Polar bear somatic cells contain 74 total chromosomes. How many chromosomes would a polar bear sperm cell contain?

37 total

Photosynthesis Reactants

6CO2 + 6H2O

Which of the following events occur during eukaryotic translation elongation?

A tRNA binds a codon and the ribosome adds amino acids from each tRNA to the polypeptide chain.

Photosynthesis Products

C6H12O6 + 6O2

Molecules brought in and used in the Calvin Cycle

CO2 NADPH

G1

Cell prepares to replicate DNA

Why do most plant leaves appear green?

Chlorophyll pigments in plant cells reflect green wavelengths of light.

Messenger RNA (mRNA)

Contains the condons for the polypeptide sequence

S

DNA synthesis

a product that donates electrons to the electron transport chain

NADH

Consider what happens to energy in photosynthesis. How does this differ from what happens to energy in cellular respiration?

In photosynthesis, energy is captured from light, whereas in cellular respiration energy is transferred from storage molecules to ATP.

What are telomeres?

the DNA located at the ends of eukaryotic DNA molecules

Initiation

the RNA polymerase binds to the group of transcription factors at he promoter -The DNA double helix unwinds and the RNA synthesis begins

chlorophyll a

violet-blue orange-red

Glycolysis is a step in the breakdown of glucose. Which of the following statements describe glycolysis?

- It is common to anaerobic and aerobic respiration - It produces a net gain of two ATP and two NADH

Molecules PRODUCED in the calvin cycle that leave the cycle

-3-carbon molecules that store energy -energy-carrier molecules that have lost some energy

Which of the following are examples of cell signaling? Choose all that apply.

-A neuron releases neurotransmitters into a synapse, triggering a target nerve cell. -When food is scarce, soil bacteria aggregate and produce fruiting bodies. -Thyroid hormone stimulates body cells to increase metabolic activity.

Molecules BROUGHT IN and used in the calvin cycle

-CO2 from outside the cell -energy-carrier molecules formed in the light-dependant reactions

Identify the key structural features of a DNA molecule.

-DNA bases are always paired purine with pyrimidine. -The backbone of DNA is made of a sugar and a phosphate molecule. -DNA strands are antiparallel and include a 5\' end and a 3\' end.

Meiosis

-Forms four haploid gametes -Contributes to genetic diversity through crossing over

Choose all the events that occur during the light-dependent reactions of photosynthesis.

-H ions are used to help produce the energy carriers, ATP and NADPH. -Electrons on special chlorophyll molecules gain energy from light. -A concentration gradient forms as excited electrons help move H ions.

Transfer RNA (tRNA)

-Hydrogen bonds with codon -Transports amino acids to the ribosome

What are the components of eukaryotic chromosomes?

-Protein -DNA

Mitosis

-Result in two diploid cells idential to parent cell -Used for asexual reproduction

Termination

-The RNA polymerase detaches from the DNA -THe RNA plymerase stops adding base pairs when it reaches a certain DNA sequence that signals the end of the gene -The RNA transcript is realeased

Unique to photosystem I

-The energized electrons are used to form NADPH after leabing this photosystem -Electrons from the electron transport chain are used to replace electrons lost from cholorphyll molecules

Calvin Cycle

-Use carbon dioxide -produce sugars -need ribulose biphosphate

Light dependant reactions

-Uses H20 -use chlorophyll to capture light energy -synthesize ATP and NADPH -Generate oxygen gas

G-Protein-linked receptors

-activation by ligand releases a protein that binds guanosine triphospate (GTP) -important for taste

Which statements describe characteristics of stomata in plants?

-are openings into a plant that are surrounded by guard cells -permit carbon dioxide to enter and oxygen to escape from a plant

Zygote

-cell resulting from the fusion of gametes -a fertilized egg cell

aerobic conditions

-citric acid cycle (Krebs Cycle) -Electron transport chain

Heterotroph

-consumers -unable to produce organic compounds from inorganic materials -cannot make their own food -depend on other organisms for energy

Cyclins

-expression levels change during phases of cell cycle -do not have enzyme function -activate cyclin-dependant kinase

Sister Chromatids

-identical copies -linked by a centromere -result of chromosome duplication

Which of the following describes crossing over?

-increases genetic variation across gametes -occurs between homologous chromosomes

Plants synthesize their own food in the form of sugars during the process of photosynthesis. Which of the following statements describe photosynthesis?

-is a cellular process that occurs in the chloroplasts of plant cells -generates sugars from the energy contained in sunlight -converts carbon dioxide to sugars, releasing oxygen

homologous chromosomes

-may have different alleles -have different parental origins -may exchange genetic material

Molecules used and regenerated within the calvin cycle

-most of the glyceraldehyde 3-phosphate (G3P) -Ribulose Bisphosphate (RuBP)

tRNA

-moves amino acids to the site where they are added to a growing peptide -has an antcodon that interacts with a specific codon from another molecule

mRNA

-moves genetic information out of the nucleus and into the cytoplasm -contains nucleotide triplets that coe for specific amino acids

Cyclin-dependent kinases

-phosphorylate specific amino acids on other proteins -require cyclin binding to function -directly activate protien important at specific phases of the cell cycle

protein kinase

-phosphorylates a proteins -binds adenosine triphosphate (ATP)

Gamete

-produced by mitosis -sperm cell

Autotrophs

-producers -many use photosynthesis to produce organic compounds -use inorganic materials to produce energy -synthesize their own food

Which of the following statements describe the significance of meiosis in most animals?

-results in haploid cells that fuse to form a cell with a full complement of chromosomes -contributes to genetic diversity, which is necessary for natural selection

Which of the following are mechanisms that a cell uses to relay an external signal during signal transduction?

-second messangers -protein phosphroylation

Unique to Photosystem II

-the hydrogen atoms from water molecules are split, producing H+ and replacement electrons for chlorophyll molecules. -Energy from electrons excited in this photosystem is used to help pump H+ ions into the thylakoid for ATP production

tumor suppressor genes

-these genes code for proteins that normally prevent uncontrolled cell division -mutations that decrease activity of these genes may lead to cancer -some products of these genes normally function in repairing damaged DNA

Proto-oncogenes

-these genes code for proteins that normally promote cell division -mutations that increase activity of these genes may lead to cancer

Which of the following describes sexual reproduction?

-two parents combine their DNA to produce an offspring -uses haploid cells produced by meiosis

ethanol fermentation

-used by yeast cells -generates ethanol

2,4-dinitrophenol (DNP) causes ____(1)____ to pass directly across the inner mitochondrial membrane instead of returning to the mitochondrial matrix through___(2)___ proteins. Because of DNP\'s effect on the mitochondrion, less energy is captured in the form of ___(3)___ and more energy is instead wasted as heat.

1- Protons 2-ATP Synthase 3- ATP

A male giant panda has 42 chromosomes in its skin cells. This represents the __1___ chromosome number. as the animal old skin dies and slough off cells nearby divide through ___2__ to produce more skin cells

1. Diploid 2. Mitosis

Light-dependent reactions of Photosynthesis Initial (1) - Final (5)

1. Photons of light excite electrons on specific chlorophyll molecules. 2. Electrons escape from chlorophyll molecules and move down an electron transport chain 3. Hydrogen ions are pumped into the interior of the thylakoid 4. H+ ions pass through an enzymeas they move out of the thylakoid 5. ATP and NADPH are produced

Arrange the steps of a G-protein signal transduction in the order that they occur.

1. a signal molecule binds to the receptor activating it 2. the receptor changes conformation and binds an inactive G protein 3. the g protein is activated by the dissociation of GDP and binding of GTP 4. The G protein dissciates from the receptor 5.The g protein activates an effector protein leading to a cellular response.

The cells produced by mitosis in this panda have a ___1___ chromosome number and are produced after __2__ are pulled apart into seperate daughter cells.

1. diploid 2.sister chromatids

Place the steps of DNA transcription in the order in which they occur.

1.The RNA polymerase attaches to the DNA strand upsteam from a gene 2.RNA polymerase pairs RNA bases with the DNA bases on the template strand 3. The RNA breaks away from the RNA polymerase and they both leave the DNA strand

During glycolysis, glucose is broken down into two molecules of pyruvic acid. How many carbon atoms are in each pyruvic acid molecule?

3 Carbon Atoms

Response

A cell reacts to a signal molecule by initiating changes in shape, activity, or behavior

At any given time, there is an array of signaling molecules in a cell\'s environment. How does a cell \"know\" which signaling molecules to respond to?

A cell responds to a signaling molecule only if the cell has the appropriate receptor.

Which of the following events occur during eukaryotic translation termination?

A protein recognizes the stop codon and the ribosome dissociates from the mRNA.

Transduction

A signal molecule induces a change in a membrance protein that activates other proteins within the cell

Which molecule is used as the primary source of chemical energy for tasks within a cell?

ATP

a product that can be used directly for energy

ATP

the direct energy source for glycolysis

ATP

Which mRNA codon functions as the start codon, directing the ribosome to begin translating the mRNA from the correct end?

AUG

Which of the following describes the way in which phosphorylation directly contributes to signal transduction?

Addition of phosphate groups alters the three-dimensional protein structure, which allows the protein to interact with new binding partners.

During which phase of mitosis do spindle fibers shorten, pulling sister chromatids apart from one another and toward opposite ends of the cell?

Anaphase

Why does arsenic and limited oxygen result in fermentation?

Arsenic prevents acetyl-CoA formation, whereas limited oxygen disables the electron transport chain.

As genetic material replicates, sister chromatids are linked in an X-shaped structure. What is the term used to describe the area where the two chromatids are linked?

Centromere

The cells that make up multicellular organisms send, receive, and respond to a variety of signals. Which of the following is an example of synaptic signaling?

Changes in a neuron\'s membrane voltage releases neurotransmitters, which travel to nearby neurons.

This substance is made up of fibers that are formed in the nucleus by supercoiling genetic material.

Chromatin

Eukaryotic DNA structure

Condensed around histone proteins DNA is linear Has repeating telomere region Arranged in multiple chromosomes

Prokaryotic DNA structure

Condensed only by DNA supercoiling DNA is circular Does not have a telomere region Arranged in a single looped structure

Replication: DNA ---> _____

DNA

This series of nucleotides encodes proteins.

DNA

Unique to individuals or species

DNA Sequences number of genes

Use the drop-up menus to complete the following sentences. disrupts cellular respiration by destroying the proton gradient in the mitochondrion.

DNP (Diet Pills)

Cytochromes are critical participants in the electron transport chains used in photosynthesis and cellular respiration. How do cytochromes donate and accept electrons?

Each cytochrome has an iron-containing heme group that accepts electrons and then donates the electrons to a more electronegative substance.

The cell cycle is a repeating sequence of events that leads to the duplication and division of a cell. Place the stages of the cell cycle in the order of their occurrence, from the earliest stage of cell growth through the latest stage of cell division.

Earliest: interphase prophase prometaphase metaphase anaphase telophase cytokenisis Lastest:

Which of the following describes what happens during mismatch repair of DNA?

Enzymes identify the recently copied DNA strand, snip out a portion of the DNA strand that contains the mismatched nucleotides, and resynthesize the segment correctly.

DNA damage can occur as a result of exposure to chemicals or ultraviolet radiation. What happens during nucleotide excision repair of damaged DNA?

Enzymes open the DNA strand, remove a segment of DNA from the strand that contains the damage, and resynthesize the correct DNA sequence.

An ATP molecule contains the nitrogenous base guanine.

False

An ATP molecule contains three AMP molecules.

False

High-energy phosphate bonds in ATP link the phosphate groups and the base adenine.

False

Dna replication steps

First 1. Heilcase unwinds the DNA double helix 2. Single-stranded DNA binding proteins bind to each template strand 3. RNA primers are added 4. DNA polymerase synthesizes DNA. 5. RNA primerfs are removed 6. DNA ligase joins DNA fragments together

Three phases in signal transduction pathway in order:

Growth factor signal molecules are released into the extracellular spaces near the cut----> 1. Protein receptors on cells near the cut bind to growth factor signal molecules 2. Growth factor signal molecules cause changes in protein receptors triggering changes in other proteins in the cells cytosol 3. Proteins in the cells cytosol activate proteins in the nucleus causeing the cell to begin the process of mitosis in response ---> Signal transducgtion pathway ends.

Bacterium

Haploid

What is the function of the proton gradient in the mitochondrion?

It is potential energy that the cell uses to generate ATP.

The cells that make up multicellular organims send, receive, and respond to a variety of signals. Which of the following is an example of direct signaling?

Junctions between adjacent plant cells connect their cytoplasms and allow them to share molecules.

Similarities between the two photosystems

Light energy us used to excite an electron on specialized chlorophyll molecules

disrupts cellular respiration by stalling the electron transport chain.

Low oxygen

(- } -)

Metaphase

Compounds produced by the electron transport chain

NAD+, FAD, H2O, ATP

Compounds that enter the electron transport chain

NADH, FADH2, O2, ADP

Molecules produced during the calvin cycle that leave the cycle

NADP+ a few of the glyceraldehyde 3-phosphate (G3P)

Modern humans share a small percentage of their DNA with Neanderthals, with the exception of modern humans of African descent. What conclusion can be drawn from this?

Neanderthals and modern humans did not interbreed until after modern humans migrated out of Africa.

Universal DNA attribute

Nucleotides A, C, G, and T -Code for amino acids -triplet codons

These discontinuous sequences of DNA nucleotides are synthesized by DNA polymerase and fused together by DNA ligase.

Okazaki fragment

Both in Itrons and Exons

Prensent in the DNA used as the template for transcription present in eukaryotic genomes

This folded amino acid chain is genetically encoded and performs specific functions in the cell.

Protein

Transcription: DNA --> ___

RNA

What happens during the elongation step of DNA transcription?

RNA polymerase moves along the template strand of the DNA creating an mRNA strand.

cellular respiration

Releases carbon dioxide occurs in both plant and animal cells

~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~ 1.

Replication

How does mitosis and cytokinesis in eukaryotes differ from binary fission in prokaryotes?

Sister chromatids attach to spindle fibers during mitosis, whereas binary fission does not use spindle fibers to separate the replicated chromosome.

What happens during anaphase II of meiosis?

Sister chromatids separate from each other and migrate to opposite ends of the cell.

During which phase of mitosis do nuclear membranes reform around the separated copies of DNA?

Telophase

Elongation

The RNA polymerase tranverses the DNA template adding complenmentary base pairs in the 5' to 3' direction -the newly transcibed RNA transcript is proofread for errors

Which of the following scenarios is a direct effect of the absence of carbon dioxide during photosynthesis?

The carbon fixation stage of the Calvin cycle would be unable to synthesize the sugar 3-PGA.

What happens during telophase II of meiosis?

The nuclear membrane begins to form around haploid sets of chromosomes.

Meiosis is a critical process for many living organisms. If an organism became unable to complete meiosis, what effect would it have on the organism?

The organism would no longer produce sex cells.

How does random fertilization increase genetic variability?

There are millions of possible chromosome arrangements for each sperm and each egg.

Which statement describes the function of photosynthetic pigments in leaves?

They absorb light energy and trap high energy electrons.

~~",~~,'~~',~~,',~~~,','~~~,', 2.

Transcription

ATP is made up of the base adenine, the carbohydrate ribose, and phosphate groups.

True

Although the path of one glucose molecule through glycolysis generates a total of four ATP molecules, there is a net gain of only two ATP for each glucose molecule that enters the pathway. Why does the passage of one glucose molecule through glycolysis have a payoff of only two ATP molecules?

Two ATP molecules are used in the initial phase of glycolysis, reducing the net gain to two ATP.

What generally causes thymine dimers to form in a strand of DNA, and why are thymine dimers a problem?

Ultraviolet light can cause thymine dimers, potentially creating a mutation that could lead to cancer.

The cells that make up multicellular organims send, receive, and respond to a variety of signals. Endocrine signaling is a form of cell-to-cell communication in which...

a cell produces a signal released into the bloodstream to be carried to specific distant organ.

The cells that make up multicellular organims send, receive, and respond to a variety of signals. Paracrine signaling is a form of cell-to-cell communication in which...

a cell produces a signal that induces changes in local, nearby, cells.

plant cell cytokinesis

a cell wall forms between daughter cells - a cell plate forms from fused vesicles

animal cytokinesis

a contractile ring pinches the cell in two -cleavage produces a furrow around the cell

Which of the following best describes a ligand?

a small molecule that influences a larger molecule when the two bind

ligand-gated ion channel

activation by ligand causes a conformational change that allows ion to cross the cell membrane -important for action potentials in nuerons

enzyme-linked receptors

activation by ligand induces a change that cause the transmembrane protein to function as an enzyme important for receiving growth factors

rRNA

acts as an enzyme for peptide synthesis

disrupts cellular respiration by stalling the conversion of pyruvate to acetyl CoA.

arsenic

The cell that produces the signal

autocrine

Which of the following molecules are used as second messengers in signal transduction pathways?

cAMP Inositol triphosphate Ca2+

Nerve cell

diploid

apple tree cell

diploid

a carbohydrate that enters glycolysis directly

glucose

Molecules made in the cytoplasm from the products of the calvin cycle

glucose and other organic molecules

Both anarobic and Aerobic conditions

glycolysis

Generates NADH or FADH2

glycolysis Citric Acid Cycle Acetyl CoA Production

These proteins regulate transcription and modifications of genetic material.

histones

which stage of the cell cycle is the longest

interphase

An anticodon is a sequence of three nucleotides that

is found on transfer RNA and is complementary to messenger RNA codons.

Two daughter strands of DNA are synthesized during DNA replication. Which term describes the new chain of DNA that begins at the replication fork and is synthesized in discontinuous fragments.

lagging strand

Which enzyme joins fragments of DNA into a continuous strand?

ligase

Needed for light-dependant reactions

light H2O molecules chloroyphll

what stage of meiosis: (~ : ~)

metaphase II

citric acid cycle

mitochondrial matrix

electron transport chain

mitochondrial membrane

a cell anywhere in the body that responds to neurohormones in the blood

neuroendocrine

Trnaslation

occurs in robosomes -produces a protein -requires tRNA

Photosynthesis

occurs in the chloroplasts of plant cells -requires sunlight to proceed -synthesizes carbohydrates to store energy

Since DNA is replicated semiconservatively, what does each new daughter cell receive from the parent cell after replication and mitosis?

one of the original strands and one new strand

Receives NADH or FADH2

oxidative phosphorylation

Select the description of an intron.

portion of a DNA sequence that is removed from pre-mRNA and not expressed in the protein

What stage of meiosis: ('O')

prophase II

Translation: RNA --> _____

protein

Cellular respiration consumes glucose during glycolysis. What product of glycolysis can be subsequently modified to enter the citric acid cycle under aerobic conditions?

pyruvate

an end product that is modified to enter the citric acid cycle

pyruvic acid

During one of the three phases of the Calvin cycle, three molecules of ATP are used to catalyze the rearrangement of five three-carbon sugars, known as glyceraldehyde-3-phosphate (G3P), into three five-carbon sugars, known as ribulose bisphosphate (RuBP). One other molecule of G3P is exported to the cytoplasm to form glucose. In which phase of the Calvin cycle does this occur?

regeneration

Protein phosphatase

removes a phosphate group from a protein releases inorganic phosphate

What is the function of the mitotic spindle?

separating sister chromatids

Small molecules and proteins can act as cellular communication signals by binding to cell receptors. A protein binds to its receptor on a cell surface and starts a biochemical chain reaction within the cell. What is the general term for this type of pathway?

signal transduction

Intracellular receptors are located in either the cytoplasm or the nucleus. Which type of ligands binds to intracellular receptors?

small lipid-soluble molecules

What is the role of second messengers in signal-transduction pathways?

small molecules or ions that transmit a signal from the exterior of the cell to the interior of a cell

Transcription

takes place in the nucleus -builds strand of mRNA

Which of the following describes a genome?

the collection of genetic material in a cell or organism

Select the description of RNA splicing.

the process by which introns are removed from pre-mRNA and exons are connected to form mature mRNA

Select the component of choloroplast that is the site of light-dependent reactions.

thylakoids

Mitosis

two identical cells diploid cells

lactic acid fermentation

used by animal cells produces lactic acid (lactate)

How can cells of different tissues respond differently to the same signal molecule?

variations in the set of proteins that the cell possesses

During which phase of mitosis does chromatin condense into chromosomes as the nuclear membrane breaks down?

Prophase

How are DNA fragments separated using gel electrophoresis?

Smaller DNA fragments move through the gel more quickly than larger fragments move.

Which of the following statements about quorum sensing is false?

The autoinducer can only act on a different cell: it cannot act on the cell in which it is made.

What contribution did James Watson and Francis Crick make to our understanding of DNA?

They pieced together the available evidence and modeled the structure of DNA.

0000000000000000000 3.

Translation

ATP contains ribose, a five-carbon sugar.

True

ATP has three phosphate groups.

True

Carotenoids

Violet-blue

Chlorophyll b

Violet-blue orange-red

Fertilization

a process fusing the nuclei of two gametes

what stage of meiosis 1: (~ : : ~)

anaphase 1

Ribosomal RNA (rRNA)

catalyzes peptide bond formation

exons only

code for a protein part of the final mRNA strand

breakdown of glucose to pyruvate

cytosol

skin cell

diploid

Both Mitosis and Meiosis

duplication of chromosomes occurs before cell division

The electron transport chain uses the transfer of ______ between protein complexes to set up a proton gradient.

electrons

a cell found anywhere in the body

endocrine

Anarobic conditions

fermentation

Meiosis

four different cells haploid cells

Itrons only

generally absent from bacterial genomes removed from inital mRNA strand prior to translation

Both photosynthesis and cellular respiration

generates ATP generates energy using a proton (H+) gradient occurs in plants requires an electron transport chain

A proton gradient is formed in the mitochondria such that the concentration of protons (H ) is higher on one side of the inner mitochondrial membrane than on the other side. What is the purpose of this proton gradient?

generates ATP in the electron transport chain

egg cell

haploid

sperm

haploid

Both the light-dependant reactions and the calvin cycle

happen inside chloroplasts in plants

Which enzyme separates the two complimentary strands of DNA during DNA replication?

helicase

Produced by light-dependant reactions

high-energy NADPH and ATP

mRNA, rRNA, tRNA

in eukaryotes can exist outside of the nucleus -composed of ribonucleic acid

Which of the following describes the effect of cyanide on cellular respiration?

inhibits the function of cytochrome c oxidase in the electron transport chain

which stage of meiosis 1: (~ : ~)

metaphase 1

Both ethanol and lactic acid fermentation

occur under anaerobic conditions regenerates NAD+ that can be used in glycolysis

a cell in another individual

pheromone

("0)

prophase

What is a promoter sequence?

region of DNA that is the initial binding site of RNA polymerase during transcription

G2

sister chromatids

Reception

specific protein signal molecules found outside a cell attach to specialized cell surface proteins