AP Bio semester test

Which of the following most likely explains how the amino acid subsitution has resulted in decreased catalytic activity by the mutated enzyme?

Which of the following most likely explains how the amino acid subsitution has resulted in decreased catalytic activity by the mutated enzyme?

The subsitution altered the secondary and tertiary structure of the enzyme so that the mutated enzyme folds into a different shape than the normal enzyme does.

Which of the following is responsible for the cohesive property of water?

Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule

A typical bag of fertilizer contains high levels of nitrgogen, phosphorusm, and potassium but trace amounts of magnesium and calcium. Which of the following best matches the fertilizer component with the molecule in which it will be incorporated by organisms in the area?

Nitrogen will be incorporated into nucleic acids

Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins?

The change leads to increased protein stability because of an increased number of S-S bonds in the tertiary structure of the proteins

Which of the following best explains the reactions of these enzymes?

Amylase aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds

Which of the following best describes a structural difference between DNA and RNA?

The backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose

A chemical binds to a protein composed of a single polypeptide chain and prevents the formation of an alpha helix that is typically formed in the absence of the chemical. Which of the following best describes the effect the chemical has on the structure of the protein?

The secondary structure held together by hydrogen bonds is affected.

Used to carry genetic code

Nucleic acids

Which part of the amino acid most likely contributes to the hydrophobic behavior of this region of the polypeptide?

Methyl (CH3) group

Which of the following best explains how water is able to move upward from the roots of a plant, through its xylem in the stem, and out of the leaves?

Water and the xylem are both polar. Water molecules have the ability to form hydrogen bonds with each other and with the walls of the xylem.

Humans produce sweat as a cooling mechanism to maintain a stable internal temperature. Which of the following best explains how the properties of water contribute to this physiological?

The high heat of vaporization of water allows the body to remove excess heat through a phase change of water from liquid to gas.

The synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct?

Water

Which of the following is most directly respobsible for water’s unique properties?

It forms hydrogen bonds

Which of the following is the key characteristic that is ultimately responsible for the unique chemical properties of each element?

Each element has a unique atomic number

Which of the following properties is common among elements in the same column of the periodic table?

They have the same number electrons in their valence shell

The nucleus of a nitrogen atom contains 8 neutrosn and 7 protons. Which of the following is a correct statement concerning nitrogen?

The nitrogen atom has a mass of 15 and an atomic number of 7.

Sulfur has an atomic number of 16 and a mass number of 32. How many electrons are needed to complete the valence shell of a sulfur atom?

2

A covalent chemical bond is one in which

outer-shell electrons of two atoms are shared so as to occupy the outer electron shells of both atoms

When two atoms are equally electronegative, they will interact to form

nonpolar covalent bonds

Unequal sharing of electrons between atoms will result in which of the following interactions?

a polar covalent bond

Which of the following molecules contains polar covalent bonds?

H2O

An ionic bond is formed by

transfer of an electron from one to another

Which of the following effects is produced by the high surface tension of water?

A water strider can walk across the surface of a small pond

Hydrophobic substances such as vegetable oil are

nonpolar substances that repel water molecules

How many molecules of water needed to completely hydrolyze a polysaccharide that is 10 monomers long?

9

Which of the following is the smallest carbohydrate?

sucrose

Why are hydrocarbons insoluble in water?

The majority of their bonds are nonpolar to covalent carbon-to-hydrogen linkages.

Which of the following statements concerning saturated fats is true?

They are generally solid at room temperature

Which of the following statements regarding lipids is true?

They are insoluble in water

Which of the following saturated fatty acids is true?

They are the principal molecules in lard and butter

Why are the vertebrate sex hormones estrogen and testosterone considered to be lipids?

They are made of fatty acids

Which two functional groups are always found in amino acids?

carboxyl and amino

Which of the following is a monomer used to build a biological polymer?

amino acid

Which of the following molecules or structures may be found in eukaryotic cells but not in bacteria?

endoplasmic reticulum

Which of the following structures will be found in nearly all eukaryotic cells?

mitochondria

Which of the following statements concerning cells of bacteria and archea is correct?

Chromosomes in both archea and bacteria contain DNA

Prokaryotes are classified as belonging to two different domains. What are the domains?

Bacteria and Archaea

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

Proteins

Which organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?

smooth endoplasmic reticulum

Which of the following statements correctly describes a function of the Golgi apparatus?

protein modification and sorting

Which organelle occupies much of the volume of a plant cell?

Central vacuole

A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, chloroplasts, and mitochondria. It could be

a plant cell but not an animal cell

Plastids are only found in which of the following types of cells or organisms?

plant cells

Which plant cell organelle contains its own DNA and ribosomes?

mitochondrion

In an animal cell, DNA may be found in which of the following organelles?

only in the nucleus and mitochondria

The fluid mosaic model of membrane structure suggests that membranes

are composed of protein molecules embedded in a fluid bilayer of phospholipids

Which of the following molecules are localized on the exterior of a phospholipid bilayer?

phosphate groups

The primary structural components of the cell membrane are

phospholipids and proteins

an integral membrane protein would have to be

amphipathic, with at least one hydrophobic and one hydrophilic region

How do unsaturated fatty acids help keep any membrane more fluid at lower temperatures?

The double bonds from kinks in the fatty acid tails that prevent adjacent lipids from packing tightly together

Which of the following molecules would you expect to diffuse through the lipid bilayer of a plasma membrane most rapidly?

O2

Water can move quickly through the plasma membrane of some cells because

it moves through the aquaporin channel proteins

Carrot slices placed in 0.2 M salt solution for several hours become flaccid (limp). Carrot slices placed in fresh water for several hours become turgid (stiff). From this we can deduce that

the fresh water is hypotonic and the salt solution is hypertonic to the cells of the carrot slices.

Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?

Water will leave the cells, causing them to shrivel and collapse

Thinking about the environments where plant and animal cells typically exist, which of the following statements is correct?

Animal cells are generally in an isotonic solution, and plant cells are generally in a hypotonic solution.

Submerging a plant in distilled water will result in

the cell becoming turgid

Based on this information, which transport mechanism is most likely responsible for glucose transport in the intestinal cells?

Facilitated diffusion

Which of the following best predicts the effect of not having ATP available to supply energy to this process?

H+ ions will stop moving through the protein

Other conditions being equal, which artificial cell is predicted to be the most efficent in exchanging oxygen with the environment by diffusion?

The cuboidal

Which of the following describes the most likely location of cholesterol in an animal cell?

embedded in the plasma membrane

Which of the following is a characteristic of mitochondria and chloroplasts the endosymbiotic theory?

Both contain DNA molecules

The cellular process of breaking down large molecules into smaller ones is defined as

catabolism

Which of the following describes the result of transferring an electron from a less electronegative atom to a more electronegative atom?

The more electronegative atom is reduced, and energy is released

Which chemical process generates the ATP produced in glycolosis?

substrate-level phosphorylation

The cellular process of synthesizing large molecules from smaller ones is defined as

anabolism

What is the source of the energy used to generate the proton gradient across the inner mitochondrial membrance?

redox reactions in the electron transport chain

Where does glycolysis occur in animal cells?

cytosol

In the complete oxidation of a molecule of glucose in aerobic cellular respiration, how many molecules of ATP are produced by substrate-level phosphorylation?

4

What is the primary function of the Calvin Cycle?

To produce simple sugars from carbon dioxide

What is the relationship between wavelength of light and the quantity of energy per photon?

They are inversely related

Generation of proton gradients across membranes occurs during which of the following reactions?

both photosynthesis and cellular respiration

Which of the following statements about the relationship between photosynthesis and cellular respiration is correct?

Cellular respiration is catabolic and photosynthesis is anabolic

A reduction in the amount of NADP+ available in plant cells in the light will ultimately result in which of the following effects?

A decrease in the rate of linear electron flow

Which of the following statements correctly describes a reaction associated with photosystem II?

Electrons releases from the P680 chlorophyll are replaced by electrons derived from water.

Which of the following reactions produces the oxygen released by photosynthesis?

splitting of water molecules

Which of the following molecules are products of the light reactions of photosynthesis are utilized in the Calvin cycle?

ATP and NADPH

The complete oxidation of two molecules of glucose in cellular respiration produces about how many molecules of ATP?

60-64

In addition to ATP, whare are the products of glycolosis?

NADH and pyruvate

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + pi to ATP?

energy released from movement of protons down their electrochemical gradient through ATP synthase

WHat is the primary role of oxygen in cellular respiration?

to serve as an acceptor for electrons and protons, forming water

Carbon dioxide is released during which of the following stages of cellular respiration?

oxidation of pyruvate of acetyl CoA and the citric acid cycle

Which of the following indicates a primary path by which electrons travel downhill energetically during aerobic respiration?

glucose→ NADH→ electron transport chain→ oxygen

A noncompetitive inhibitor decreases the rate of an enzyme reaction by

changing the shape of the enzyme active site

The active sit of an enzyme is the region that

binds substrates for the enzyme

Which of the following statements regarding enzymes is true?

Enzymes increase the rate of a reaction by lowering the activation energy barrier

Which of the following statements is true for all exergonic reactions?

The reaction proceeds with a net release of free energy

Which of the following is the most comprehensive definition of metabolism in living organisms?

Metabolism consists of all the energy transformation reactions in an organism

Which of the following best explains the buildup of lactic acid in individuals with the mutation?

Cells undergo fermentation because pyruvate cannot be metabolized to proceed into the Krebs cycle

A researcher claims that increased atmospheric carbon dioxide levels cause increased growth rates in plants. Which of the following statements best supports the researcher’s claim?

Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds

A researcher claims that the synthesis of ATP from ADP and inorganic phosphate is essential to cellular function. Which of the following statements best help justify the researcher’s claim?

ATP hydrolysis os an energy-releasing reaction reaction that is often coupled with reactions that require an input of energy

Which of the following was the dependent variable in the researcher’s experiment?

pH

Based on the date in Table 1, which of the following is the earliest time point at which there is a statistical difference in average pH between the control and treatment groups?

35 minutes

On average, more ATP can be produced from an NADH molecule than can be produced from a molecule of FADH2. Based on Figure 1, which of the following best explains the difference in ATP production between these two molecules?

The electrons of FADH2 are transferred through three complexes of the electron transport chain whereas those of NADH are transferred through all four complexes.

Which of the following best predicts the effect of disrupting the proton gradient in BAT?

Electron transport and oxidative phosphorylation will be decoupled, generating more heat but less ATP

Based on the data in the table, which of the following best explains the effects of rotenone on cellular respiration?

Treated cells are not able to break down NADH because certain enzymes of the electron transport chain are inhibited

Which of the following best describes the role of water in photosynthesis?

Water molecules donate electrons to the electron transport chain

If the experiment is repeated at pH 11, the observed activity level of the enzyme will most likely be

lower than the level at pH 9

Beginning with a fertilized egg, how many cells would be present in an embryo following a series of five cell divisions?

32

Which of the following components make up eukaryotic chromatin?

DNA and proteins

Besides the ability of some cancer cells to divide uncontrollably, what else might logically result in formation of a tumor?

lack of appropriate cell death