BIO 101 - CHAPTER 1, 2, 3, 4

Many names for sugars end in the suffix

-ose.

All proteins can be made from varying combinations of ___________amino acids.

20 ***There are 20 amino acids, all with different properties.

Lactase deficiency is more common in Asian, Native American, Mediterranean and some African populations than it is among people with northern or western European ancestry. How would you explain why this is so?

Although most mammals, including humans, are not able to digest the milk sugar, lactose, after infancy, the ancestors of northern and western Europeans relied on dairy products as an important part of their food supply. When other food sources were in low supply, mutations that allowed the expression of the enzyme lactase to persist past childhood conveyed an advantage to adults who were able to include dairy products in their diet. ***The ability of adults to digest lactose is a result of a mutation related to the enzyme lactase. Lactose-tolerant adults make lactase. Lactose-intolerant adults do not make lactase.

Prokaryotic cells are found in the domain(s) _____.

Bacteria and Archaea

Which of the following statements about cellular metabolism is false?

Cellular metabolism occurs in animal but not plant cells.

_____ is the most abundant organic compound on Earth.

Cellulose ***Cellulose, a component of plant cell walls, is the most abundant organic compound found on earth.

_____ are found only in plant cells, but _____ are found in both plant and animal cells.

Central vacuoles; ribosomes ***Central vacuoles are found only in plant cells. Ribosomes are found in both plant and animal cells.

Which of the following statements regarding the endomembrane system is false?

FALSE: The endomembrane system is a system of interrelated membranes that are all physically connected. ***FACTS: The endomembrane system includes the nuclear envelope. The endomembrane system includes the rough and smooth endoplasmic reticulum. The endomembrane system is involved in the synthesis, storage, and export of important molecules.

Which of the following is part of the endomembrane system?

Golgi apparatus ***The endomembrane system includes the ER, the Golgi apparatus, lysosomes, and vesicles. It manufactures, processes, and transports lipids and proteins. The Golgi apparatus processes and packages proteins.

When the human virus HIV first appeared, the mortality rate was close to 100%. However, recent information shows some individuals are unaffected by the virus. Why is this not surprising?

Humans are genetically diverse, and some are immune to the virus. ***As in all populations, individuals in human populations vary in their traits. Some individuals have genetic modifications that do not allow entry of HIV into their immune cells, thus making them immune to the virus and its effects. Such individuals could be favored by natural selection.

How are ionic bonds formed?

In ionic bonds, one atom gives up an electron to a second atom. ***For example, CaCl2 (calcium chloride) is formed by the give and take of electrons. Calcium gives up 2 electrons, and each chlorine atom absorbs an electron.

Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?

Keep the cough drop whole. This maintains the smallest surface-to-volume ratio and slows the dissolution of the cough drop.

Which of the following statements regarding lactose tolerance is true?

Lactose tolerance has evolved independently in multiple different human populations. ***Lactose tolerance arose independently in Europe, in multiple places in East Africa, and likely elsewhere.

Which level in the hierarchy shown is a community?

Level C. (All organisms in the savannah)

Which plant cell organelle converts chemical fuel into packets of chem

Mitochondrion. ***In both plant and animal cells, it's the mitochondria that convert chemical fuel into packets of chemical energy that can power the cell.

Which of these is a scientific hypothesis?

My excessive urination may mean that I have high blood pressure.

Which of the following statements about the cytoskeleton is false?

Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place ***FACTS: The cytoskeleton helps to support cells. The cytoskeleton plays an important role in amoeboid motion. The cytoskeleton is composed of three types of fibers: microfilaments, microtubules, and intermediate filaments.

Which of the following is a function of the central vacuole?

Storing compounds produced by the cell ***One of the functions of the central vacuole is to store compounds produced by the cell.

In the figure below, what leads directly to the reproductive success of these beetles?

The beetles with traits best suited to the environment survive ***Those individuals with heritable traits best suited to the environment will leave the greatest number of healthy, fertile offspring

Which of the following describes the function of the chloroplast?

The chloroplast converts light energy to chemical energy. ***The chloroplast makes food for the plant cell by converting light energy to chemical energy.

What is the relationship between the Golgi apparatus and the plasma membrane?

The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane. ***Transport vesicles from the Golgi move to the plasma membrane for export. In some cases the finished products become part of the plasma membrane or part of another organelle.

Two proteins have the same number and type of amino acids. How is it that they can have different shapes and therefore different functions?

The order in which the amino acids are arranged differs between the two proteins. ***It is the sequence and arrangement of the 20 amino acids that determines the shape of a protein and thereby the function. Different sequences can yield different proteins.

Lactose is a disaccharide (two monosaccharides joined together). To metabolize lactose, individuals require an enzyme known as lactase. What is true about this reaction?

The reaction hydrolyzes the sugar ***Lactose is hydrolyzed, or spilt, into two monosaccharide subunits.

What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?

They are constructed of interrelated membranes ***Each of these organelles is a member of the endomembrane system and is constructed of the same type of membrane.

Which of the following statements is true about the chemical nutrients in an ecosystem?

They cycle within the ecosystem and are constantly reused ***Nutrients cycle through the ecosystem, being returned for availability by processes such as decomposition.

A pesticide kills 95% of a pest population. What will be the result of the continued application of this pesticide?

Through time, the pesticide will become less effective at killing the pest ***As a result of the application of the pesticide, those individuals that are resistant will have greater reproductive success than individuals that are sensitive to the pesticide

Which of the following describes a covalent bond?

Two or more atoms share electron pairs ***Covalent bonds occur when two or more atoms share one or more pairs of electrons.

A glucose molecule is to starch as __________.

a nucleotide is to a nucleic acid ***Nucleotides are the monomers that make nucleic acids, just as glucose is the monosaccharide from which starch is constructed.

Glycogen is _____.

a polysaccharide found in animals ***Animals store energy in the form of glycogen.

The teeth of grain-eating animals (such as horses) are usually broad and ridged. This makes the teeth suitable for grinding and chewing. Meat-eating animals (such as lions) have pointed teeth that are good for puncturing and ripping flesh. This illustrates

a result of natural selection as well as the connection between form and function

A hydrogen bond is _____.

a weak interaction between two molecules ***Hydrogen bonds involve polarity, or polar interactions. Hydrogen bonds are weak chemical bonds that are very important in the chemistry of life.

Can you label the atoms, partial charges, and types of bonds associated with these water molecules?

a. H b. O c. H d. (+) e. (-) f. hydrogen bond g. polar covalent bond

Can you complete this concept map about protein structure and function?

a. amino acids b. functions c. peptide bonds d. central carbon e. primary structure f. secondary structure g. R group h. tertiary structure i. quaternary structure

Can you label the structures of a prokaryotic cell?

a. fimbriae b. nucleoid c. plasma membrane d. cell wall e. capsule f. flagella g. bacterial chromosome h. ribosomes

Can you label the sugar molecules, type of reaction, and atoms or molecules shown in the chemical reaction below?

a. monosaccharide b. dehydration reaction c. disaccharide d. OH e. H f. H20

Can you label this diagram showing how nutrients and energy flow in an ecosystem?

a. sunlight b. producers c. chemical energy d. consumers e. heat f. CO2 g. O2

Human proteins, such as insulin, can be produced by bacterial cells. This is possible because __________.

all organisms share a common genetic code ***With only a few minor exceptions, the genetic code is universally shared by all organisms.

The membranous compartmentalization of a cell

allows different chemical conditions to be maintained in different parts of the cell

Carbohydrates are mainly used in our bodies _____.

as fuel ***Simple sugar molecules are a major fuel for cellular work.

Mitochondria are found in _____.

both plant cells and animal cells ***Mitochondria are found in nearly all eukaryotic cells.

Tay-Sachs disease

causes an accumulation of lipids in brain cells.

The nucleoid region of a prokaryotic cell

contains the cell's DNA

The function of the chloroplast is to _____

convert light energy to chemical energy ***The function of the chloroplast is to convert light energy from the sun to the chemical energy of a glucose molecule.

The structural framework in a cell is the

cytoskeleton ***The cytoskeleton is the structural framework in a cell ("cyto" refers to cell and "skeleton" refers to a structural framework).

Where would ribosomes be located that are responsible for producing enzymes which play a role in sugar metabolism?

cytosol ***The first steps of sugar metabolism occur within the cytosol. Therefore, the ribosomes in the cytosol are responsible for making the necessary enzymes.

Look at the table shown below. When referring to bonds, the symbol = means that the bond is a(n) _____.

double covalent bond ***The double line indicates that the atoms are sharing two pairs of electrons.

A theory is a(n)

explanation of an idea that is broad in scope and supported by a large body of evidence.

Of the following sugar molecules, which is not a disaccharide?

fructose ***Fructose is a monosaccharide, not a disaccharide

Which of these is a polysaccharide?

glucose lactose sucrose galactose *cellulose* ***Cellulose is a carbohydrate composed of many monomers

The storage form of carbohydrates is ________ in animals and ________ in plants.

glycogen; starch

Researchers set up a study to determine whether large doses of a nutritional supplement would shorten the length of time it takes to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of group A took 3,000 mg of the supplement daily. Group B received 3,000 mg of a placebo (sugar pill). At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both group A and group B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in the length of time the colds lasted.

group A only

The oil and vinegar in your salad dressing remain separate from one another due to the _____ properties of the oil.

hydrophobic ***Oils and other fats are water-fearing or hydrophobic and will not dissolve in water-based solutions such as vinegar.

A scientist notes that an ornamental grass grown in a creek bed is taller than the same type of grass grown on the creek bank. The scientist suspects that this difference is due to water availability. This proposed explanation is a(n) __________.

hypothesis ***A hypothesis is a proposed explanation for the observation of the warning light. The actual reason may be different and would only be found through making a prediction and testing that prediction.

The plant cell wall

is a protective structure made of cellulose fibrils ***The cell wall is a structure that protects the plant cell and is made of cellulose fibrils.

Protein synthesis requires the use of mRNA, which

is translated by the ribosomes into the amino acid sequences of proteins

The maximum size of a cell is limited by _____.

its need for enough surface area to make exchanges with its environment ***Because volume increases at a faster rate than surface area, large cells have proportionately less plasma membrane surface area.

Peptide bonds

link amino acids ***formed by dehydration synthesis

Cholesterol belongs to which class of molecules

lipids ***Steroids, such as cholesterol, are lipids characterized by a carbon skeleton consisting of four fused rings.

The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. In other words, fatty acids are not being broken down. Which organelle is most likely failing to function correctly?

lysosome ***This organelle functions to remove unwanted or unneeded material from the cell.

Which of the following organelles breaks down worn-out organelles?

lysosomes ***Lysosomes contain digestive enzymes and break down worn-out organelles.

Tay-Sachs disease results from the malfunction of

lysosomes.

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA ***The "m" in mRNA stands for "messenger"; mRNA is the messenger that carries genetic instructions from the nucleus to the cytoplasm.

glucose + glucose —> _____ by _____.

maltose + water ... dehydration synthesis ***Maltose is the disaccharide formed when two glucose molecules are linked by dehydration synthesis.

Mitochondria appear in the greatest numbers in cells that are _____.

metabolically active ***Mitochondria are the sites of cellular respiration, the catabolic process that generates ATP by extracting energy from food molecules, with the help of oxygen.

The protein actin is a component of a(n) __________.

microfilament ***Microfilaments are primarily composed of actin, a globular protein

Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?

microtubules ***Vesicles travel along microtubules as they move from one part of the cell to another.

The internal skeleton of a cell is composed of _____.

microtubules, intermediate filaments, and microfilaments ***These three types of fibers make up the cytoskeleton.

Which of these is a source of lactose?

milk ***Lactose is the sugar found in milk.

Where in a cell is ATP made?

mitochondria ***ATP is made in mitochondria.

Which model is best studied through a systems approach?

model of the biogeochemical cycling of nutrients

A diet high in animal products and hydrogenated vegetable margarine may increase the risk for heart disease. This is because

most animal fats are saturated and many hydrogenated vegetable margarines contain high levels of trans fats.

Can you label the structures of a plant cell?

not in animal cell a. central vacuole b. cell wall c. chloroplast d. golgi apparatus e. smooth endoplasmic reticulum (ER) f. rough endoplasmic reticulum (ER) g. nucleus h. mitochondria others: ribosomes cytoskeleton plasma membrane channels between cells

Can you label the structures of an animal cell?

not in most plant cells centriole lysosome flagellum a. cytoskeleton b. ribosomes c. nucleus d. smooth endoplasmic reticulum (ER) e. cytosol f. golgi apparatus g. rough endoplasmic reticulum (ER) h. mitochondrion i. plasma membrane

Where is the genetic information of the cell stored?

nucleus ***DNA is the genetic information of the cell, and it is stored in the nucleus.

The genetic center of the eukaryotic cell is the __________.

nucleus ***The nucleus is the genetic center of the cell, and it contains the hereditary information.

A property of life known as energy processing refers to the fact that living things __________.

obtain energy from their environment and use it to power their own activities and chemical reactions ***All organisms must process energy in order to survive.

A hydrogen atom has one electron. How many covalent bonds can hydrogen form?

one

Chloroplasts are found in __________.

plant cells and some protists ***Chloroplasts are lens-shaped organelles found in leaves and other green organs of plants and photosynthetic protists.

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?

plasma membrane ***The plasma membrane surrounds the cell and regulates the movement of materials into and out of the cell.

In a water molecule, hydrogen and oxygen are held together by a ________ bond.

polar covalent

The atoms in the molecule of water shown below are held together by which type of bond?

polar covalent bond ***The hydrogen and oxygen atoms do not equally share their electrons, which results in the formation of electronegative oxygen atoms and electropositive hydrogen atoms. These are then able to interact with other water molecules to form hydrogen bonds.

A protein containing more than one polypeptide chain exhibits the ________ level of protein structure.

primary, secondary, tertiary, and quaternary structure

There are a number of properties that all organisms share. In humans, exposure to ultraviolet light can result in a darkening of the skin. What kind of property is this?

response to the environment ***A suntan is a response by skin cells to the environment. The suntan protects the body from absorbing an excess of solar radiation

The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The pigment melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function. Melanocytes use many enzymes to produce melanin. Based on their function, you would expect melanocytes in the skin to have a higher than usual number of

ribosomes

Which of the following structure(s) is/are found in prokaryotic cells?

ribosomes ***Both prokaryotic and eukaryotic cells do have ribosomes.

Much of the intracellular structure of a eukaryote cell is involved in protein synthesis. The accompanying figure shows the amounts of protein in cells at different parts of the cell cycle between two cell divisions. G1 is a stage just after the cell has divided, and G2 is the stage just before the cell divides again. S is a stage when the cell is synthesizing material such as DNA, mitochondria, and other organelles. The protein measured in the cells was likely synthesized by

ribosomes.

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by

ribosomes. ***Ribosomes dock on the rough ER, and proteins are completed inside the rough ER.

You would expect a cell with an extensive Golgi apparatus to _____.

secrete a lot of material ***The Golgi apparatus intercepts ER vesicles, modifies the contents for export, and repackages the material in a Golgi vesicle that can fuse with the plasma membrane.

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER) ***The smooth ER makes lipids.

Which meal is high in fiber, low in saturated fats, and high in unsaturated fats?

spaghetti noodles with olive oil and broccoli

When you eat a plant, you derive energy from the stored __________, but not from the __________ component.

starch ... cellulose ***The starch is ultimately hydrolyzed into glucose, which can be used for energy, while the cellulose comprises the insoluble fiber passing through your digestive tract unchanged.

The Golgi apparatus

stores, modifies, and packages proteins

Which part of the mitochondrion shown enhances its ability to produce ATP by increasing the surface area of a mitochondrial membrane?

structure D

The plasma membrane would fit into which general function category?

support, movement, and communication ***The plasma membrane is an important structure for cell communication with the external environment.

Which of the following is a function of the rough endoplasmic reticulum?

synthesizing receptor proteins ***These proteins are made by the rough endoplasmic reticulum and then processed by the Golgi apparatus before being inserted into the cell membrane.

To be of value to science, hypotheses must be __________.

testable ***Hypotheses must be phrased in such a way that predictions can be made and tested

To be scientifically valid, a hypothesis must be

testable and falsifiable

A company was testing a new drug they thought would help decrease the risk of transmitting viruses from mother to fetus. In an experiment to test the compound, a worker gave 400 pregnant female rats a small dose of the experimental drug and inoculated each with a type of virus known to cause disease in rats. An additional 400 pregnant rats were given only the virus. Of the rat pups born to the females that received both the virus and the drug, 203 showed symptoms of the disease; of the rat pups born to the females that received only the virus, 207 showed symptoms. From this test, we can best conclude __________.

that the drug seems to have little effect on viral transmission at the dosage given ***Approximately equal numbers of pups were affected in both groups, indicating that the drug was not effective.

The primary structure of a protein is

the amino acid sequence of the polypeptide chain.

Amino acids can be distinguished from one another by

the chemical properties of their R groups.

Membrane proteins are synthesized by ribosomes that are attached to __________.

the endoplasmic reticulum ***Ribosomes bound to endoplasmic reticulum generally make proteins destined either for inclusion into membranes; for packaging within certain organelles, such as lysosomes; or for export from the cell. The ribosomes attached to its surface are what give the RER its "rough" appearance

As we respire, we release CO2. The carbon in this CO2 is obtained from __________.

the food we eat ***Animals eat plants, and plants fix carbon dioxide from the atmosphere into sugars through the process of photosynthesis. Humans then eat the plants (or animals that have eaten the plants), obtaining carbon, which is then metabolized to produce CO2. The CO2 is then exhaled back into the atmosphere.

Which of the following characteristics of a protein will remain intact if the protein is denatured?

the number of amino acids in the protein

The tertiary structure of a polypeptide refers to

the overall three-dimensional structure

To enter or leave any cell, substances must pass through _____.

the plasma membrane ***The plasma membrane defines the boundary of the cell.

Proteins differ from one another because

the sequence of amino acids in the polypeptide chain differs from protein to protein.

The chemical energy used by most organisms for metabolism and growth ultimately comes from __________.

the sun ***Energy for life ultimately comes from the energy of the sun, trapped by photosynthetic organisms.

The partial charges in this water molecule occur because of _____.

the unequal sharing of electrons between hydrogen and oxygen ***Because oxygen is more electronegative than hydrogen, electrons of the polar bond spend more time closer to the nucleus of the oxygen atom, resulting in a slight negative charge on the oxygen atom and slight positive charges on the hydrogen atoms.

The function of the nucleolus is

to manufacture ribosomal RNA.

In an ecosystem, energy

typically flows from producers to a series of consumers

A fatty acid containing at least one double bond is called _____.

unsaturated ***An unsaturated fatty acid has one or more double bonds.

As cell size increases, the

volume increases proportionally more than the surface area.

Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?

whether or not the cell is partitioned into compartments by internal membranes ***Prokaryotic cells lack any internal membranous compartmentalization whereas eukaryotic cells have membrane-bound organelles.