Biology - week 6 respiration and enzymes

In what molecule(s) is the majority of the chemical energy from pyruvate transferred during the citric acid cycle?

NADH and FADH2

The energy from the electrons in NADH and FADH2 fuel what process in the electron transport chain?

The pumping of H+ across the cristae of the mitochondrion

A small amount of ATP is made in glycolysis by which of the following processes?

Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

What is the total production of ATP, NADH, and FADH2 in the citric acid cycle from one molecule of glucose?

Two ATP, six NADH, and two FADH2

Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step __________.

enables the cell to recycle the reduced NADH to oxidized NAD+

The function of cellular respiration is to __________.

extract usable energy from glucose

Which of the following pairs of pathways and their location in the cell is incorrectly matched?

Citric acid cycle: cytosol

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?

The citric acid cycle

A molecule becomes more oxidized when it __________

loses an electron

Cells must regulate their metabolic pathways so that they do not waste resources. What is the most common mechanism that regulates cellular respiration in most cells?

Feedback inhibition of glycolysis

Put the phases of cellular respiration in order.

1st-Glycolysis 2nd-Pyruvate oxidation 3rd-Citric acid cycle 4th-Oxidative phosphorylation

Put these cellular respiration events in order

A glucose molecule is split Pyruvate is oxidized Acetyl CoA is oxidized ATP is synthesized by the ATP synthase enzyme

Consider this reaction: Ae- + B → A + Be- Which are correct?

Ae- is the reducing agent. B is the oxidizing agent.

Most of the ATP in cellular respiration is produced by the process of chemiosmosis. How does this process produce ATP?

H+ flows across the inner mitochondrial membrane through the enzyme ATP synthase.

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of _____.

NADH

Regarding substrate phosphorylation, which are correct?

Occurs during the citric acid cycle Occurs during the glycolysis phase of respiration An enzyme catalyzes the formation of ATP by direct transfer of a phosphate group to ADP from an intermediate molecule.

Drugs known as uncouplers facilitate diffusion of protons across a membrane. With an uncoupler, what will happen to ATP synthesis and oxygen consumption if the rates of glycolysis and the citric acid cycle stay the same?

Oxygen consumption will stay the same. ATP synthesis will decrease.

Regarding oxidative phosphorylation, which are correct?

Produces ATP by using energy derived from the redox reactions of an electron transport chain ATP synthase enzyme uses elctrochemical energy to add an inorganic phosphate to ADP. Accounts for almost 90% of the ATP generated by respiration Uses a proton gradient across the membrane

Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2?

The combination of the citric acid cycle and electron transport

During the energy investment phase of glycolysis, __________.

glucose is phosphorylated before it is split into two three-carbon molecules

In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced.

glucose; oxygen

During the energy payoff phase of glycolysis, __________.

NADH and ATP are produced

Glucose is the primary fuel for cellular respiration. Which of the following molecules can also be used by cellular respiration to generate ATP?

All of the listed responses are correct. Amino acids Fatty acids Glycerol

During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes?

At the end of the electron transport chain to accept electrons and form H2O

Consider a reaction: A + B → C + D where A reduces B. Which are correct?

B accepts electrons. A gives up electrons.

Consider the summary equation for cellular respiration: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy Which are correct?

C6H12O6 gives up electrons. Glucose is the reducing agent. The reaction is exergonic. O2 accepts electrons

Fermentation by itself produces no ATP but keeps glycolysis going, which produces a small amount of ATP. How does fermentation do this?

Fermentation oxidizes NADH to NAD+, which facilitates the production of ATP in glycolysis.

Which are correct? (related to fermentation)

Fermentation requires pyruvate. Fermentation produces NAD+.

In which process is glucose oxidized to form two molecules of pyruvate

Glycolysis

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

Glycolysis

Which are correct? (referring to glycolysis )

Glycolysis requires NAD+. Glycolysis produces NADH.

What is the role of oxygen in the electron transport chain?

It is reduced to form water.

Which statement correctly describes the difference between alcohol fermentation and lactic acid fermentation?

Lactic acid fermentation produces lactate, and alcohol fermentation produces ethanol.

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

Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation

All of the processes involved in cellular respiration produce ATP. Which of the following processes produces the most ATP?

Oxidative phosphorylation

Match the phase of cellular respiration with its products (per molecule of glucose)

Oxidative phosphorylation- About 26-28 ATP Glycolysis- Two molecules of pyruvate, two ATP, and two NADH Pyruvate oxidation- Acetyl CoA and CO2 Citric acid cycle- Two ATP, six NADH and two FADH2

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?

Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH.

Most of the electrons removed from glucose by cellular respiration are used for which of the following processes?

Reducing NAD+ to NADH in glycolysis and the citric acid cycle AND producing a proton gradient for ATP synthesis in the mitochondria.

Which of the following metabolic pathways produce(s) the most ATP, per glucose molecule metabolized, during cellular respiration?

The electron transport chain and oxidative phosphorylation

The ATP synthase in a human cell obtains energy for synthesizing ATP directly from which of the following processes?

The flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme

Muscle tissues make lactate from pyruvate to do which of the following?

regenerate NAD+