Biology Exam 2

Considering the ATP cycle, which of the following would have the most potential energy to perform work for cell activities?

ATP

ATP releases energy when

a phosphate is removed.

Which of the following is best associated with a coupled reaction?

The breakdown of ATP generally releases more energy (and heat) than is needed to power the metabolic reaction.

The part of the enzyme into which the substrate fits is called the

active site.

What process typically regulates the enzymes involved in metabolic reactions?

feedback inhibition

What function do the carrier proteins embedded in the cell membrane serve?

facilitated diffusion

Which of the following is a mechanism used to regulate enzyme activity?

feedback inhibition

Simple diffusion of molecules occurs

in non-living systems as well as living systems.

Molecules move from greater to lesser concentration through a carrier protein in

facilitated diffusion. (2)

During an osmosis experiment in class, you look at some cells under the microscope. You notice the cells look crenated. What type of solution were the cells immersed in?

hypertonic

A white blood cell surrounds and engulfs a bacterial cell. This process is called

phagocytosis.

The concentration of calcium in a cell is 3%. The concentration of calcium in the surrounding fluid is 1%. Which of the following processes could the cell use to obtain more calcium?

active transport

A tube with a membrane covering the bottom is placed in a beaker. The membrane allows water to flow through but not salt or glucose. If the tube contains an aqueous solution with 12% salt and 6% glucose and the beaker contains an aqueous solution with 13% salt and 10% glucose, what would happen to the level of the water in the tube?

The level of the solution in the tube would lower because there are more dissolved solutes present in the beaker.

If blood cells are placed in a hypotonic solution, the cells will

swell due to osmosis.

Which of the following is an example of osmosis?

Cells in our kidneys reabsorb water to reduce the amount of water lost in our urine.

Eggs are often preserved in a 20-30% salt solution called brine. How does this method prevent contamination by microorganisms?

Bacteria can't survive in a hypertonic solution because they lose water.

ATP is a good source of energy for a cell because

its breakdown is coupled with energy-requiring reactions.

Enzymes are usually named based on the substrate that they bind. This is possible because

each type of enzyme generally only binds one specific substrate.

Enzymes are able to speed up the rate of a reaction by

lowering the energy needed for the reaction to proceed.

Which of the following terms best describes entropy?

disorder

The innermost compartment of a chloroplast formed by the interconnected thylakoids is the

thylakoid space.

Inside the chloroplasts, chlorophyll is found in the

thylakoid membrane.

Which of the following events takes place in the Calvin cycle?

CO2 is converted into G3P

In photosynthesis, the light reactions________ while the Calvin cycle________.

capture solar energy to produce ATP and NADPH; uses ATP and NADPH to produce sugar

The light reactions produce________, which are used in the Calvin cycle. The Calvin cycle releases________, which return to the light reactions.

ATP and NADPH; ADP and NADP

The light reactions of photosynthesis are said to be similar to a battery because they form a current. In which direction do the electrons of this circuit flow?

H2O → PSII → electron transport chain → PSI → electron transport chain → NADPH

Which of the following is a function specific to photosystem I (PSI)?

produce NADPH

How does ATP synthase obtain the energy to produce ATP?

Hydrogen ions flow down a concentration gradient from the thylakoid space to the stroma through ATP synthase, releasing energy that can be used to produce ATP from ADP + Pi.

Chlorophyll is to the light reactions as________ is to the Calvin cycle.

RuBP

The production of glyceraldehyde 3-phosphate (G3P) in the Calvin cycle requires six molecules each of ATP and NADPH. Another three molecules of ATP are then used in the cycle. What is the purpose of these three additional ATP molecules?

to regenerate the starter molecule RuBP

Which compounds link the light reactions with the Calvin cycle reactions?

ATP and NADPH (2)

Replacement electrons for the reaction center of photosystem II are derived from

H2O.

The three stages of the Calvin cycle reactions are

CO2 fixation, CO2 reduction, and RuBP regeneration.

ATP and NADPH are both used during the Calvin cycle. What is the function of each?

ATP supplies energy and NADPH supplies electrons for reducing power.

Energy to drive the formation of ATP in photosynthesis is derived from

the H+ gradient.

The O2 given off during photosynthesis is derived from

H2O.

Sucrose, cellulose, amino acids, and starch are all made from what starter molecule in plants?

glyceraldehyde 3-phosphate (G3P)

The difference between bundle sheath cells in C3 and C4 plants is that

the bundle sheath cells in C4 plants have chloroplasts, while those in C3 plants do not.

CAM photosynthesis limits CO2 fixation to night-time hours in order to

open stomata only at night, limiting water loss because of heat and low humidity.

The light reactions act like a battery that stores the energy needed to power the reactions of the Calvin cycle. This energy from the light reactions is stored in the form of

ATP and NADPH.

The number of ATP produced during aerobic cellular respiration from one glucose molecule is usually________.

36-38

The final acceptor for electrons in aerobic cellular respiration is________.

oxygen

Which of the following is the correct sequence of events in cellular respiration?

glycolysis → preparatory reaction → citric acid cycle → electron transport chain

What molecule most directly provides the energy you need for your muscles to contract?

ATP

Which of the following is the opposite of cellular respiration?

photosynthesis

Where in the cell are both NAD+ and FAD reduced to form NADH and FADH2?

mitochondrial matrix

The energy source that drives the production of ATP in oxidative phosphorylation is the________.

the diffusion of H+ (hydrogen protons) down their electrochemical gradient

The production of ATP in glycolysis and the citric acid cycle is accomplished by________.

substrate-level ATP synthesis

During cellular respiration, the energy in glucose is ultimately converted to________.

ATP and heat

Energy is released from ATP when________.

a phosphate group is removed from ATP yielding ADP + P + energy

Two ATP are invested in glycolysis in order to________.

break glucose into two molecules

A product of glycolysis is________.

pyruvate

Where in the cell does glycolysis occur?

cytoplasm

Glycolysis and the citric acid cycle are similar in that they both produce________.

NADH and ATP

If three molecules of glucose went through glycolysis and eventually into the citric acid cycle, how many times did the preparatory reaction occur?

six

As a result of glycolysis, there is a net gain of________ ATP.

2

What two stages of cellular respiration produce the carbon dioxide you exhale?

preparatory reaction and citric acid cycle

The energy of the electrons passing along the electron transport chain is ultimately used to produce________.

ATP

The citric acid cycle starts with________ and yields________.

acetyl-CoA, NAD+, FAD, and ADP; carbon dioxide, NADH, FADH2, and ATP

Which of the following is necessary for the complete breakdown of glucose?

oxygen

Nuclear division occurs during

M phase

What structure holds two sister chromatids together?

centromere

Which of the following represents the phases of mitosis in their proper sequence?

prophase, metaphase, anaphase, telophase

Chromatin wrapped around histones form a bead-like structure known as a

nucleosome.

The G2 checkpoint prevents the cell cycle from continuing until

the DNA has finished replicating.

A mutation results in a cell that no longer produces a normal protein needed for the M-phase checkpoint. Which of the following would likely be the immediate result of this mutation?

the cell would never leave metaphase

If a cell is inhibited during the S phase of its cycle, it will not reproduce due to lack of

DNA synthesis.

Which of the following occurs prior to prophase?

synthesis of DNA

Some of the drugs used in chemotherapy work by

preventing spindle formation.

If the production of cyclins halted during the cell cycle

the cell would not proceed to the next phase of the cell cycle.

Which of the following would increase your risk of cancer?

avoiding a high-fiber, low-sodium diet

Apoptosis

can be used to remove damaged or malfunctioning cells.

Which of the following does NOT describe a cancer cell?

a cell regulated by contact inhibition

The term metastasis refers to the fact that cancer cells tend to

spread

Cancer is a disorder in which some cells have lost the ability to control their

rate of cell division.

Cells that do not receive the correct signals to move from G1 into S phase will enter G0 and therefore will

not undergo mitotic division unless it later receives the go-ahead signal.

Plant cells and animal cells differ in cytokinesis because

plant cells need to build a cell wall, while animal cells do not.

Which of the following is a characteristic of cancer cells?

the nucleus is abnormally shaped.

A proto-oncogene differs from a tumor suppressor gene because a proto-oncogene

stimulates cell division in a normal cell, whereas a tumor suppressor gene inhibits cell division.

A tumor suppressor gene undergoes a mutation that causes it to lose its normal function. What would be the most likely result of this mutation?

The cell no longer responds to signals that cause it to stop dividing or undergo apoptosis.

Which of the following statements is correct?

Meiosis involves two divisions and produces four nonidentical gametes.

One major difference between meiosis I and meiosis II is that

crossing-over occurs in prophase of meiosis I but not in prophase of meiosis II.

During metaphase I, the homologous chromosomes align at the spindle equator with each homologue

facing opposite spindle poles.

Which of the following processes does not contribute to creating genetic variability in the offspring?

mitosis

During the G1 stage of interphase, a diploid organism contains how many copies of each gene?

2

In each gamete following telophase II, how many copies of each gene is/are present?

1

A homologous pair is composed of

two chromosomes with two sister chromatids each.

During crossing-over,

genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles.

The term tetrad refers to

two homologous chromosomes each comprised of two sister chromatids.

The failure of sister chromatids to separate during meiosis is called

nondisjunction.

Within the human life cycle, which of the following processes and products are paired correctly?

oogenesis - 1n gamete

Metaphase II is more similar to metaphase of mitosis than to metaphase I because

in metaphase II, chromosomes align separately at the spindle equator.

During meiosis II,

chromosomes line up separately, with sister chromatids facing opposite spindle poles.

Which of the following human syndromes is a monosomy?

Turner syndrome

The failure of sister chromatids to separate in one of the cells during meiosis II would result in how many normal gametes?

2

Klinefelter syndrome can result from nondisjunction during

meiosis I or II in either parent.

The first 22 pairs of chromosomes are called________ while the 23rd pair are known as the________ chromosomes, which code for gender.

autosomes: sex

Which pair of chromosomes on a karyotype would show you the sex of a baby?

23rd pair

Which of the following is an inaccurate statement about crossing-over?

Crossing-over occurs between sister chromatids.

Crossing-over between sister chromatids does not result in recombination of genetic material, while crossing-over between nonsister chromatids does because

sister chromatids have identical alleles, while nonsister chromatids have different ones.