Biology- Unit II

Some membrane transport mechanisms utilized by cells are active, while others are passive. Which of the following are ways in which active and passive mechanisms differ?

-Passive mechanisms like diffusion can only transport form hight concentration to low-Active mechanisms can be used to transport substances from low concentration to high-Active mechanisms require the use of cellular energy in the form of ATP

List these substances in order of which diffusion occurs most easily. Place the substance with easiest diffusion at the top.

1. Air 2. Liquid 3. Semi-solid

Which of the following are characteristics of C4 plants? select all that apply

1. C4 plants store carbon dioxide temporarily as oxaloacetate 2. C4 plants are found in hot, dry climates 3. C4 plants have a new photosynthetic rate two or three times greater than C3 plants 4. C4 plants experience more photorespiration than C3 plants.

What would happen if the stomata of a leaf remained closed all day? Select all that apply.

1. Carbon dioxide in the air spaces of the leaf would decrease 2. Oxygen in the air space would increase 3. Photorespiration would increase in C3 plants

Which of the following is a common photosynthetic pigment found in plants? Select all.

1. Chlorophyll a 2. carotenoids 3. chlorophyll b

G3P (glyceraldehyde-3-phosphate) can be use plants to form which of the following? Select all that apply.

1. Fatty acids 2. Amino acids 3. Starch

If plants were no longer able to perform the light reactions and they could only utilize the Calvin cycle, which of the following would be true? Select all that apply.

1. Plants would not produce oxygen 2. G3P would be produced in much smaller quantities

Which of the following are major functions of the plasma membrane? Select all that apply.

1. Regulation of molecules and ions that pass into and out of the cell 2. Maintaining connections between adjacent cells 3. Production of proteins used in construction of cell wall

Which of the following is a product of cell respiration?

1. Water 2. ATP

One turn of the citric acid cycle produces

3 NADH, 1 FADH2, 1 ATP

Complete oxidative breakdown of glucose results in ________ ATP molecules.

36

Aerobic cellular respiration yields about ____ of the energy of glucose in ATP molecules.

39%

Which of the following substrates is essential to an organism that utilizes photosynthesis?

6H20

Picture on my phone

A is amino acids; B is glucose; C is glycerol; D is fatty acid

Oxygen production in photosynthesis involves all of the following? A. photosystem I B. photosystem II C. splitting of water D. light reactions E. Calvin cycle

A. photosystem I B. photosystem II C. splitting of water D. light reactions

______ represent(s) the first reactant(s) of this metabolic pathway and ____represent(s) the end product(s) of this pathway. A->B->C->D->E

A;E

Which of the following is an endergonic reaction?

ADP + P -> ATP

In this, B-> C is coupled with ADP->ATP. Categorize the reactions as endergonic or exergonic. A->B->C->D->E

ADP->ATP is endergonic and B-> C is exergonic

What type of transport mechanism is required to move sodium ions against their concentration gradient?

Active

In which substance(s) can diffusion occur?

Air, liquid, semi-solid

Which of the following is an example of potential energy?

All are examples (snickers, an apple, a glass of milk)

Why is it beneficial for pyruvate to be reduced via fermentation when oxygen is not available?

All choices are advantages

Having similar ____________ would allow tissues and organs to be transplanted easily. A. cell recognition proteins B. major histocompatibility complex proteins C. carbohydrate chains in the cell membrane D. all of the choices are involved in tissue transplantation

All of the choices

Which of the following is a true statement about enzyme inhibition?

All of the statemnets are true

Which statement is not true about how various conditions will affect the activity of an enzyme?

An enzyme's activity is generally reduced by an increase in substrate concentration

How is a respirometer used to measure fermentation in this experiment?

By the size of the gas bubble produced

Photorespiration occurs mainly in

C3 plants

Some parasites and disease agents regularly change their identity before our immune system can build up substantial antibodies. How can cells change their chemical identity on a regular basis? A. Rapid evolution produces mutations. B. A new phospholipid bilayer is generated to replace the old layer. C. Because the membrane is "set," the cell must reproduce and then the cell with the old membrane must die. D. Cells eliminate all surface proteins and present only a naked lipid bilayer. E. Different glycolipids and glycoproteins are produced internally and moved into the plasma membrane.

Different glycolipids and glycoproteins are produced internally and moved into the plasma membrane.

In general, what is the effect of the type of medium on diffusion rate?

Diffusion rate is greater in fluid media than solid

If your experiment were allowed to continue for an indefinite period of time, what would eventually happen?

Dynamic equilibrium when all the solutes ae evenly distributed

C->D is coupled with the reaction ATP->ADP. Based on this information the reaction C->D is____. A->B->C->D->E

Endergonic

Which process is responsible for moving cellular wastes across the cell membrane and out of the cell?

Exocytosis

Which of the following coenzymes will accept two electrons and two hydrogen ions during the oxidation of glucose?

FAD

An enzyme is a protein that causes the rate of the reaction to slow down

False

Chemiosmotic ATP synthesis occurs in the cytosol of the cell. True False

False

Each molecule of NADH produced in the mitochondria provides enough energy to form two ATP molecules

False

Fluidity of a membrane increases as the percentage of unsaturated fatty acids in the phospholipids decreases.

False

Glycolysis produces 1 pyruvate and 3 NADH coenzymes.

False

In the sodium-potassium pump, sodium is transported in to the cell and potassium is transported out of the cell using ATP energy

False

Photorespiration is the process by which light is used to release the stored energy in carbohydrate molecules to perform all work in plant cells.

False

In osmosis,water will move in what direction?

From the area with lower solute concentration (higher water concentration) to high solute concentration (lower water concentration)

______ is a product of the Calvin cycle that is used to form glucose phosphate, amino acids or fatty acids

G3P

In which medium are solvent molecules most widely spread?

Gas

Solute molecules can move most freely through___.

Gas

In which type(s) of medium does molecular movement occur?

Gas, liquid, semi-solid

Which carbohydrate is the primary or preferred starting compound for glycolysis and the fermentation pathway

Glucose

Which solute in your experiment diffused from the dialysis tubing into the beaker?

Glucose

Which statement is not true about the proteins in the plasma membrane?

Glycoproteins contain carbohydrate chains that are oriented toward the inner surface of the membrane

Astrophysicists explain that eventually the sun will swell to become a red giant, engulf the earth and "burn out" with all forms of energy dispersing in a final "heat death." Compared with conditions today, the entropy of the universe then will A. have increased greatly. B. have decreased greatly. C. remain the same because energy cannot be created or destroyed.

Have increased greatly

A 10% glucose solution is placed in the thistle tube. The thistle tube is placed in a beaker that contains a 5% glucose solution. The solution in the thistle tube is _______ to the solution in the beaker.

Hypertonic

Dialysis tubing is rather stiff. How will you get it pliable so that you can tie a tight knot?

I'll soak it in water until its pliable

The carrier molecules of the electron transport system are located in the ______________

Inner mitochondrial membrane

What happens when iodine is added to a solution containing starch?

Iodine changes from light yellow to blue-black in color

The average diffusion rate in a semi-solid like agar is around 50mm/h over the first 15 minutes. What can you say about the diffusion rate in a liquid based on your results.

It is greater than the diffusion speed in a semi-solid.

Oxygen diffuses from the blood to the tissues of the body. Which of the following statements is true about the movement of oxygen?

It moves from an area of high concentration in the blood to low concentration in the tissues

Which of the following best describes molecular motion?

Molecules move in random directions

Which of the following examples the mechanism of diffusion?

Molecules spread randomly from areas of higher concentration to areas of lower concentration.

In the region of high concentration of each substance, why is there a net movement of molecules outward?

More molecules collide within the region of high concentration

Air is a solution of gases. It is composed of 1% water vapor, 0.04 carbon dioxide, 21% oxygen, and 78% nitrogen. Which of the gases is the solvent?

Nitrogen

A living organism represents stored energy in the form of chemical compounds. When an organism dies, what happens to this stored energy?

The chemical compounds in cells lose their organization over time because there is no longer an input of energy to maintain the organized state

What determines the direction of diffusion?

The concentration gradient - high concentration to low

Suppose solute molecules are highly concentrated and that diffusion happens fast. What will the distribution of solute be like after a long time?

The concentration of solute will be equal everywhere

A concentration gradient exists in a solution when...

The concentration within the solution is not the same everywhere.

During the conversion of glucose into a free form of energy, only some of the energy is converted into usable ATP. What happens to the rest of the energy?

The energy is converted to heat

How does the speed of diffusion depend on the speed of the molecules?

The faster the molecules move, the greater the diffusion speed.

To what does the term stroma reger?

The fluid-filled space of the chlorplast

Which of the following situations is most likely to produce a heart attack?

The gap junctions have collapsed and they do not allow the correct flow of ions from one cell to the next

The ammonium chloride cloud forms closest to the substance with the higher molecular weight because:

The higher molecular weight substance diffuses more slowly than the lighter one

What conditions must be present before a solute can diffuse across a membrane?

The membrane must be permeable to the solute There must be unequal concentrations on either side of the membrane

What explains that the ammonium chloride cloud forms closer to the HCL source?

The molecular weight of HCL is greater than the molecular weight of ammonia and diffusion speed decreases as molecular weight increases

Which of the following is an example of active transport through a cell membrane?

The movement of chlorine ions from an area of low concentration on one side of the membrane to an area of high concentration on the other side of the membrane

Which of the following is true with respect to plant cell walls?

There is a greater amount of cellulose in secondary cell walls than in primary cell walls.

Solutions with a high solute concentration have less water than solutions with a low solute concentration. Keeping this in mind, which of the following explains the nature of osmosis?

There is a greater chance that more molecules will move across the membrane from the side with lower solute concentration to the side with higher solute concentration.

The color spreads outward because..

There is a net movement of each substance from an area of high concentration to low concentration.

What happens during diffusion?

There is a net movement of molecules from areas of high concentration to areas of low concentration.

Characterize these reactions involved in the Calvin cycle.

These reactions are involved in the reduction of CO2. Energy is required in the form of ATP, which is hydrolyzed to ADP. The substrate BPG is reduced, while the coenzyme NADPH is oxidized

Why are plants green?

They reflect green wavelengths of light and absorb other colors of the visible light spectrum

An extracellular matrix helps some cells to adhere to neighboring cells.

True

Chloroplasts are capable of performing photosynthesis which is the most common anabolic process on the planet

True

Fossil fuels are full of energy stored from photosynthesis millions of years ago.

True

Phosphoenylpyruvate carboxylase (PEPCase) fixes carbon dioxide(C1) to PEP(C3) to form oxaloacetate(C4) within mesophyll cells of the C-4 plants.

True

Receptor-mediated endocytosis involves the use of specific proteins in the cell membrane

True

The first event in the Calvin cycle is the attachment of carbon dioxide to the five-carbon RuBP molecule, which forms a six-carbon molecule that breaks down into two three-carbon PGA molecules. True False

True

The first event in the Calvin cycle is the attachment of carbon dioxide to the five-carbon RuBP molecule, which is a reaction assisted by large quantities of RuBP carboxylase enzyme.

True

glycolysis occurs before the preparatory reaction and the citric acid cycle

True

Which of the following describes the structure of a disaccharide?

Two monosaccharides bonded together

Some bacteria are strict aerobes and others are strict anaerobes. Some bacteria, however, are facultative anaerobes and can live with or without oxygen. If given the choice of using oxygen or not, which should a facultative anaerobe perform?

Use oxygen since aerobic metabolism provides more ATP per molecule of carbohydrate broken down than anaerobic metabolism.

What is the solvent in biological solutions such as cytoplasm and blood?

Water

What will happen to a celery stick that is placed in a glass of water?

Water will move into the celery cells from the surrounding solution

In which organisms is ethanol produced as a result of fermentation

Yeast

What does the dialysis tubing represent in your experiment

a cell membrane

All life forms currently have a basic cell membrane so we hypothesize that the earliest cells also had membranes. It is likely that the primordial environment was acidic. In order for a cell to function in this type of environment, the cell membrane would have to include

a proton (H+) pump.

To what does the term grana refer?

a stack of thylakoid membrane structures

The activity of an enzyme might be increased by all of the following except ________? a. An increase in substrate concentration. b. a vitamin c. a two to four degree increase in temperature d. the presence of other enzymes

d. the presence of other enzymes

What is osmosis?

diffusion of water across a semi permeable membrane

What is the purpose of adding iodine in this experiment

it will indicate the presence of starch

The action spectrum of photosynthesis shows a high light absorption for violet/blue and orange/red and a low absorption for green/yellow. If we were to set up an experiment where narrow bands of unicolored light were shown on an aquatic plant such as ELODEA, and we counted the number of bubbles of oxygen produced as an indicator of photosynthesis rate, how would the graph appear

just like the action spectrum with peaks at violet/blue and orange/red and trough at yellow/green

Protons (H+) accumulate in the thylakoid space during electron transport between photosystems I and II. Which of the following describes what will happen to these protons next?

moves from the thylakoid space to the stroma through an ATP synthase complex channel that generates ATP.

Adult humans cannot synthesize _____ out of the _____ common amino acids.

nine: twenty

Diffusion is a passive process because...

no cellular energy is used for this mechanism

Red blood cells come in many "blood types" including type A, type B, type AB, type O (lacking proteins A and B), Rh positive, Rh negative (lacking Rh+) and many others. If blood transfused, the recipient detects any new or "foreign" proteins. These blood type proteins are

on the outer surface of the red blood cell membrane

The most important contribution of the citric acid cycle to cellular respiration is

oxidation of metabolite molecules and the corresponding reduction of coenzymes.

What are the end products of photosynthesis?

oxygen and carbohydrateP

In a phospholipid bilayer, the

phosphate heads are oriented toward the exterior of the cell or toward the cytoplasm

Which of the following plants is an example of a CAM plant?

pineapple

Which of the following organisms are capable of photosynthesis

plants, algae, and some bacteria

Which cell junction will allow the movement of molecules between two plant cells

plasmodesmata

While we are sitting down to lunch we are consuming _______ energy which will then be converted into ______ energy as we work until dinner time.

potential; kinetic

The preparatory reaction converts

pyruvates into acetyl CoA and carbon dioxide.

Dialysis tubing is selectively permeable. This means that...

some solutes will pass through and others will not

The majority of the carbon dioxide we exhale is produced in

the citric acid cycle

Which process reduces molecular oxygen to water?

the electron transport system

How is the concentration gradient of water related to osmotic pressure?

the greater the concentration of water across a membrane, the greater the osmotic pressure

Coupling occurs when the energy released by an exergonic reaction is

used to drive an endergonic reaction

Which of the following is the reason why plants wilt if they are watered with a salt solution?

wilting results from the loss of water

Which of these processes occurs in the cytosol?

glycolysis

The correct sequence for aerobic metabolic breakdown of glucose is

glycolysis—preparatory reaction—citric acid cycle—electron transport system.

The greater the concentration gradient, the ________ the diffusion rate.

greater

Freshwater protozoans react to a/an _____ environment by removing water through _____.

hypotonic, a contractile vacuole

A 10% glucose solution is placed in the thistle tube. The thistle tube is placed in a beaker that contains a 5% glucose solution. Where is the highest concentration of water found?

in the 5% solution

Some desert beetles can live out their life without ever drinking liquid water. They survive on "metabolic water," which

is water formed during the electron transport chain

What are the end products of photosynthesis?

glucose and oxygen

Which of the following substrates are required for cellular respiration?

glucose and oxygen

The first phase of aerobic cellular respiration is

glycolysis

During the light reactions, what structure is responsible for absorbing the solar energy?

Chloroplast

Which factor determines the direction of diffusion in all cases?

Concentration gradient

In order for diffusion to occur, there must be a:

Concentration gradient.

Which of the following labels is incorrectly identified? (PICTURE)

D refers to a product

ATP is considered a high-energy compound because under cellular conditions, 7.3 kcal per mole of energy is released when a bond is broken between: A. the base adenine and the sugar ribose. B. the adenosine and the phosphate groups. C. the base adenine and the phosphate groups. D. the adenosine diphosphate and the third phosphate. E. All of the bonds release energy as ATP is completely broken down.

D. the adenosine diphosphate and the third phosphate

Imagine a person has a genetic disorder that prevents them from producing the protein collagen, what types of cellular issues will they be faced with?

The cell would not have the ability to resist stretching

Which of the following is NOT associated with animal cells?

Plasmodesmata

Suppose you have solute molecules at a very high concentration at a specific location in a solvent. All molecules move around randomly. What will happen over time

Solute molecules will spread out evenly.

Which best describe the second law of thermodynamics?

Some useful energy is lost as heat whenever an energy transfer occurs

Which solute was too large to diffuse through the membrane?

Starch

Which of the following carbohydrates is a disaccharide

Sucrose

Lactose is milk sugar, and humans produce substantial lactase enzyme to digest it when we are infants. However, we soon lose some or even all of our lactase after childhood. In such cases, undigested lactose passes to the lower intestine where bacteria break it down into lactic acid and CO2, causing painful gas bloating. This problem could be avoided by

Taking lactase enzyme tablets or avoiding all dairyproducts

While science is not yet able to describe the phenomenon of "thinking" in physical terms, we can be certain that it is a process involving the metabolism of brain cells. With positron emission tomography (PET scan) it is possible to inject short-lived isotopes and image the regions of the brain that have the most active metabolism during various mental activities. For different mental functions, different regions and amounts of nerve cells become active. However, A. the cellular energy expended in "thinking" must be less than the chemical bond energy supplied in food to these brain cells. B. "thought" cannot be linked to cell processes because energy is not related to matter. C. since thoughts can occur over and over, the requirement for a continual input of energy to prevent entropy does not apply to this cell activity. D. "thinking" is beyond the scope of science to study.

a. the cellular energy expended in "thinking" must be less than the chemical bond energy supplied in food to these brain cells.

The first reaction in the citric acid cycle is binding

acetyl CoA to a C4 molecule.

Which type of reaction requires oxygen as a substrate?

aerobic

Energy coupling of endergonic and exergonic reactions within cells

all choices

Eukaryotic cells are substantially larger than bacterial cells and average over 20 times more volume-per-surface-area than bacterial cells. How can the eukaryotic cell membrane provide this higher rate of exchange of materials?

all choices are correct

If there are twelve different intermediate products produced during production of a molecule in a cell, we can expect that there

are about twelve enzymes, at least one responsible for each step in the metabolic pathway

Degradative reactions

can drive anabolism.

endergonic reactions

can only occur if there is an input of energy

For fatty acids to enter the citric acid cycle of aerobic respiration, the fatty acids must be:

converted to acetyl groups

identify "a"

cristae

Whether in a gas, liquid, or a semi-solid, diffusion always occurs_______.

from high to low solute concentration

When an electron has been excited to a higher energy state, it can then drop back to the original level, re-emitting the light as fluorescence. When chlorophyll is extracted in solution, and a bright red or blue light is shown on it, the chlorophyll fluoresces brightly. However, when the chlorophyll is packaged inside chloroplasts and the red or blue light is turned on, there is no fluorescence. This most likely indicates that

excited electrons are transferred to electron acceptors in the chloroplast.

Which process produces alcohol or lactate?

fermentation

The metabolic pathway below involves how many possible chemical reactions? A->B->C->D->E

four