Biology Chapter 7

In cellular respiration glucose is _____ to CO2 and oxygen is ___ to water.

Glucose is oxidized to CO2 Oxygen is reduced to water

A decrease in glucose / no change in CO2 or O2 / and an increase in ATP and NADH are events that occur in ______.

Glycolysis

The first stage in the production of ATP via the oxidation of glucose molecules is referred to as _________.

Glycolysis

ATP and NADH are both produced in _____.

Glycolysis and the CAC

In which order does one molecule of glucose undergo cellular respiration?

Glycolysis, pyruvate oxidation, citric acid cycle, oxidative phosphorylation.

Redox reactions may involve the transfer of _______.

H+ (hydrogen ions)

During a redox reaction, oxidizing agents may accept _______.

H+ ions

Due to the pumping action of the ETC, protons have a high concentration in the ______ and a low concentration in the _______.

High: intermembrane space Low: mitochondrial matrix

A molecule that is _____ loses electrons. A molecule that is _____ gains electrons.

Oxidized- loses Reduced- gains

During a redox reaction, _______ accept electrons.

Oxidizing agents

Which stage of cellular respiration produces CO2 as a waste product?

Pyruvate oxidation and the citric acid cycle

During a redox reaction, a molecule that has gained atoms is said to be ______.

Reduced

An organism that carries our cellular respiration in its mitochondria:

could be a cell from a terrestrial (land) plant

The loss of electrons is referred to as:

oxidation

During a redox reaction, if a molecule accepts electrons, it has been _____.

reduced

The first phase of glycolysis required the input of two ATP molecules. It is therefore _______.

Endergonic.

What might increase PFK-1 activity?

1) A mutation that increases binding affinity for f6P 2)A mutation that increases binding affinity for AMP 3) A mutation that decreases binding affinity for ATP.

How would you explain why fermentation yield so much less ATP than that of aerobic cellular respiration?

1) The end products of fermentation are only partially oxidized, compared to the end product of aerobic cellular respiration (CO2) 2) The end products of fermentation retain much more of the starting free energy.

What is the overall process of aerobic cellular respiration?

1) glucose 2) electron carriers 3) ETC 4)water

What is the missing component in the reaction: (NAD+) + (____) + (H+) = NADH

2 e-

At the end of glycolysis, the carbon originally found in the starting glucose molecule is now present in ____.

2 pyruvate molecules

The energy released by transferring electrons along the ETC is stored as potential energy in the form of __________.

A proton gradient

Pyruvate oxidation does not produce _____.

ATP

During the CAC:

ATP is synthesized by substrate-level phosphorylation

Each molecule of acetyl CoA that enters the CAC carries two of the carbon atoms from the original starting molecule. These carbon atoms will ultimately leave the CAC as carbon atoms in _______.

CO2

Glycolysis is a series of chemical reactions (both endergonic and exergonic) by which the cell can obtain ATP. NAD+ plays a crucial role in the reactions of glycolysis by _______.

Accepting electrons during glycolysis, with the overall result that glucose is partially oxidized to pyruvate.

The enzyme PFK-1 is thought of as a metabolic "valve" that regulates the rate of glycolysis. What is an example that correctly identifies allosteric activator and inhibitor of their action?

Activator: ADP Inhibitor: citrate

During a redox reaction, the molecule that "causes" the other to gain or lose electrons is referred to a the _______.

Agent

What would increase PFK-1 Activity?

An increased concentration of AMP. This is an example of allosteric regulation. An increase in enzyme activity could result from either increasing the activators or decreasing the inhibitors.

Animals breathe in air containing oxygen and breathe out air containing less oxygen. The consumed oxygen is used _______.

As an electron acceptor in the respiratory ETC.

How might biomass be lost in a penguin?

Biomass is converted to CO2 and H2O and is then released.

Glycolysis does not produce ______.

CO2

What is the fully oxidized product that results from the pyruvate oxidation stage of cellular respiration?

CO2

In eukaryotes, fermentation takes place in the ______.

Cytoplasm

How do different sugars enter glycolysis?

Different sugars can be modified to form different intermediates of glycolysis.

In pyruvate oxidation, the electron donor is ______ and the electron acceptor is _____.

Donor: pyruvate Acceptor: NAD+

The majority of energy captured in the CAC is in the form of ______.

Electrons donated to NAD+ and FAD

Which molecule(s) serve as electron donors for the mitochondrial ETC?

FADH2 and NADH

In a plant cell, the oxidative phosphorylation stage of cellular respiration is carried out in the cytoplasm. True or False?

False

Oxidation is the gain of electrons. True or False?

False

True or False: Fermentation occurs only in anaerobic conditions?

False

True or False: Fermentation produces more ATP than aerobic respiration.

False

ATP is not generated directly in the CAC. Instead, an intermediate is first generated by substrate-level phosphorylation. The intermediate is ________.

GTP

What is an input but not an output of glycolysis?

Glucose

Glycolysis results in the partial oxidation of glucose to pyruvate. This means that _____.

In the process of the conversion of glucose to pyruvate, some potential energy is transferred to NADH and ATP.

What would decrease PFK-1 activity?

Increasing the concentration of citrate This is an example of allosteric regulation. Decreasing enzyme activity could be a result of increasing the inhibitors or decreasing the activators.

During the CAC what happens to the coenzyme A that is part of Acetyl-CoA?

It is recycled for use in other reactions.

What happens to pyruvate during fermentation.

It is reduced to ethanol or lactic acid.

In which compartment does pyruvate oxidation take place?

Mitochondrial matrix

The CAC takes place in the ______.

Mitochondrial matrix

What product of the pyruvate oxidation stage of cellular respiration will have the two electrons that are lost from pyruvate?

NADH

The CAC is a cycle because the starting molecule ______ is regenerated at the end.

Oxaloacetate

During glycolysis, ______ phosphorylation adds phosphate groups to ADP by _____.

Substrate level phosphorylation Enzymatic transfer

During the pyruvate oxidation stage of cellular respiration, what occurs?

The formation of NADH. The formation of Acetyl-CoA. The formation of CO2. The oxidation of pyruvate.

Where are protein complexes I through IV of the ETC located?

The inner membrane of the mitochondria

Even though the full oxidation of glucose is exergonic, some of the reactions in cellular respiration are endergonic. True or False?

True

Glycolysis is:

anaerobic

Protons in a mitochondrion flow through an ATP synthase from the: A. intermembrane space to the matrix. B. matrix to the intermembrane space. C. intermembrane space to the cytoplasm. D. cytoplasm to the intermembrane space.

intermembrane space to the matrix: The ETC transforms the energy from the high energy electrons of FADH2 and NADH into an electrochemical gradient by pumping protons from the mitochondrial matrix into the intermembrane space. Those protons flow back into the matrix by passing through a special enzyme embedded in the membrane called ATP synthase.