BIO 202 Quiz Questions

EXAM II: Chapters 9-14

Which polymers are composed of amino acids?

proteins

Which of the following is not attached to the central carbon atom in an amino acid?

an oxygen

Which part of an amino acid is always acidic?

carboxyl functional group

How many molecules of water are required for the hydrolyzation of a polymer that is 22 monomer-long cellulose molecule?

21

Which of the following is correct regarding starch and cellulose?

they are polymers of glucose

An amino acid is to a protein as a glucose molecule us to _______

glycogen

Which of the following is a biological advantage of storing glucose molecules in branches polymers?

they have more sites for enzymatic attack than do unbranched polymers

In the reaction that builds a fat, _____ groups react with _____ groups.

hydroxyl; carboxyl

In fat synthesis, _____ and fatty acids combine to make fats plus ______.

glycerol; water

A plant with unique photosynthetic pigments has leaves that appear reddish yellow. Which of the following wavelengths of visible light are most effectively absorbed by this pigment?

violet and blue

Researchers discovered that carbon fixation in spinach leaves utilizes 45,000 molecules of ATP and 30,000 molecules of NADPH in an hour. The deficit in ATP required for carbon fixation is most directly made up for by which of the following processes?

cyclic electron flow

Which of the following statements best describes how a reducing agent in is chemically altered in a biological redox reaction?

It loses a hydrogen atom and loses potential energy.

Under which conditions will plant cell mitochondria actively oxidize pyruvate and carry out oxidative phosphorylation?

in all cells, with or without light

In autumn, chlorophyll is degraded in the leaves of deciduous trees. Which of the following statements best explains the change in color from green to shades of yellow, orange, or red?

Other pigments such as carotenoids remain in the leaves after the chlorophyll is degraded.

In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the net production of which of the following sets of molecules?

ATP, CO₂, and ethanol

New biosensors, applied like a temporary tattoo to the skin, can alert endurance athletes that they are about to "hit the wall" and will find it difficult to continue exercising. These biosensors monitor lactate present in sweat during strenuous exercise. Which of the statements below best explains the use of lactate as an indicator of exercise capacity?

During anaerobic respiration, lactate levels increase when muscles cells need more energy; however, muscles cells eventually fatigue, thus athletes should modify their activities to increase aerobic respiration.

What types of cells carry out ATP synthesis by chemiosmosis?

all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors

Photosynthesis is a redox reaction. H₂O is __________ during the light reactions and CO₂ is __________ during the Calvin cycle.

oxidized, reduced

Which of these equations best summarizes photosynthesis?

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

The Calvin Cycle occurs in the ______ of the chloroplast.

stroma; the fluid-filled space surrounding the thylakoids

Which of the following statements best describes the relationship between the wavelength of light and the quantity of energy per photon?

They are inversely related.

Exposing inner mitochondrial membranes to ultrasonic vibrations will fragment the membranes and pieces will reseal to form small vesicles that contain the intermembrane space. These vesicles can transfer electrons from NADH to oxygen and synthesize ATP. Which of the following statements best describes what will happen to the vesicles when NADH is added?

The inside of the vesicles will become acidic.

In a plant, which of the following reactions produces molecular oxygen (O₂)?

the light reactions alone

Beta oxidation generates substrates for cellular respiration through catabolism of which of the following molecules?

fatty acids

When a cell is deprived of oxygen, which of the following processes will be inhibited first?

the electron transport chain

Which of the following processes is directly associated with photosystem I?

receiving electrons from the thylakoid membrane electron transport chain

When a glucose molecule loses a hydrogen atom in an oxidation-reduction reaction, the glucose molecule is ________.

oxidized

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Dogs affected with this disorder most likely display which of the following symptoms?

They are lethargic and readily tire from exercise.

Which of the summary statements below best describes the results of the following reaction?

C₆H₁₂O₆ is oxidized and O₂ is reduced.

Which of the following statements best describes a characteristic of C₄ plants?

They are able to fix CO₂ at lower CO₂ concentrations and higher oxygen concentrations than C₃ plants.

In chloroplasts, the photosynthetic electron transport chain acidifies which of the following cellular compartments?

thylakoid space

Depletion of which of the following molecules from the mitochondria will most directly inhibit the citric acid cycle?

NAD⁺

Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops.

In the absence of oxygen, electron transport stops. NADH is no longer converted to

NAD⁺, which is needed for the first three stages of cellular respiration.

P680⁺ is said to be the strongest biological oxidizing agent. The strong oxidizing potential of P680⁺ is essential for its function because it ________.

obtains electrons from the oxygen atom in a water molecule

Which of the following statements describes a primary benefit of having photosystem reaction centers composed of several structurally different pigments?

This arrangement enables the plant to absorb light energy of a variety of wavelengths.

What are the products of linear electron flow in the light reactions of photosynthesis?

ATP and NADPH

Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?

glycolysis and fermentation

Carbon fixation involves the addition of carbon dioxide to _____.

RuBP

After 3-PGA is phosphorylated, it is reduced by _____.

NADPH

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?

3

Which of the following statements best describes the relationship between photosynthesis and cellular respiration?

Photosynthesis stores energy in complex organic molecules; cellular respiration releases energy from complex organic molecules.

Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?

oxidation of NADH to NAD⁺

The mechanism of photophosphorylation is most similar to which of the following processes?

oxidative phosphorylation in cellular respiration

Catabolism of fatty acids produces two-carbon molecules that are converted to acetyl CoA. The acetyl CoA molecules will most likely be metabolized in aerobic cellular respiration by which of the following mechanisms?

directly entering the citric acid cycle

In which cellular structure are the enzymes of the Calvin cycle localized?

stroma of the chloroplast

High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location than the active site. This is an example of which of the following?

allosteric regulation

Which of the following statements best describes the conditions under which the Calvin cycle and cellular respiration occur in plants?

In most plants, the Calvin cycle occurs only during the day, and cellular respiration occurs during the day and at night.

Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?

pyruvate, ATP, and NADH

In which reactions of cellular respiration does substrate-level phosphorylation occur?

in both glycolysis and the citric acid cycle

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

It joins Okazaki fragments together.

What process repairs damage to a preexisting double helix?

nucleotide excision repair

Which of these is a difference between a DNA and an RNA molecule?

DNA is usually double-stranded, whereas RNA is usually single-stranded.

Nucleic acids are assembled in the _____ direction.

5' to 3'

A sample of double-stranded DNA contains 28% thymine. Approximately what percent of the nucleotides in this sample will be guanine?

22%

Which of the following is most likely to result if a cell is unable to produce histone proteins?

the cell's DNA could not be packed into its nucleus

Which of the following is a reason that a new DNA strand elongates only in the 5' to 3' direction during DNA replication?

Dehydration reactions require a free -OH group.

Which of the following is true of DNA during interphase?

it exists as chromatin and is less condensed than mitotic chromosomes

Which of the following statements correctly describes the difference between ATP used in metabolism and the nucleotides used as a building block during DNA synthesis?

The nucleotides have the sugar deoxyribose; ATP has the sugar ribose.

True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.

True

Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis?

Topoisomerase

Short segments of newly synthesized DNA are joined into a continuous strand by _____.

ligase

The first step in the replication of DNA is catalyzed by _____.

helicase