Bio 1 exam 3

How are the light reactions and the Calvin cycle connected?

The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle returns ADP, Pi, and NADP+ to the light reactions.

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

100%

Starting with one molecule of glucose, the energy-containing products of glycolysis are

2 NADH, 2 pyruvate, and 2 ATP.

In glycolysis, what starts the process of glucose oxidation?

ATP

How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation?

Both electron transport and ATP synthesis would stop.

Which of these is NOT a product of glycolysis? NADH FADH2 ATP pyruvate

FADH2

Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. Which of these statements is the correct explanation for this observation? Oxygen is an input to acetyl CoA formation. 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. ATP is needed to convert pyruvate to acetyl CoA. Without oxygen, no ATP can be made in oxidative phosphorylation. Oxygen is required to convert glucose to pyruvate in glycolysis. Without oxygen, no pyruvate can be made.

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.

Why are carbohydrates and fats considered high energy foods?

They have a lot of electrons associated with hydrogen.

The organic carbon in a tree comes primarily from

air.(co2 in the air)

where does glycolysis occur?

cytosol

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

pyruvate, ATP, and NADH

In glycolysis, ATP molecules are produced by _____.

substrate-level phosphorylation

The ATP made during glycolysis is generated by

substrate-level phosphorylation.

NADPH is produced by

the citric acid cycle.

In the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis?

two ATP

In glycolysis there is a net gain of _____ ATP.

2

How many NADH are produced by glycolysis?

2

Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy

C6H12O6 is oxidized and O2 is reduced.

NADH and FADH2 are both electron carriers that donate their electrons to the electron transport chain. The electrons ultimately reduce O2 to water in the final step of electron transport. However, the amount of ATP made by electrons from an NADH molecule is greater than the amount made by electrons from an FADH2 molecule. Which statement best explains why more ATP is made per molecule of NADH than per molecule of FADH2?

Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor.

n the combined processes of glycolysis and cellular respiration, what is consumed and what is produced?

Glucose is consumed, and carbon dioxide is produced.

You can think of a cell as a car factory. The control center holds the directions for making the car. There are assembly lines for constructing the engine and frame of the car. After the main structure of the car is built, the finishing touches are added (paint, leather seats, chrome bumpers). Lastly, the car is shipped to different car dealers. Which organelle would be responsible for putting the finishing touches on the car (protein)?

Golgi apparatus

A glucose molecule is completely broken down to carbon dioxide and water in glycolysis and the citric acid cycle, but together these two processes yield only a few molecules of ATP. What happened to most of the energy that the cell obtains from the oxidation of glucose?

It is stored in NADH and FADH2

Which of the following describes the process of glycolysis? It represents the first stage in the chemical oxidation of glucose by a cell. It converts one glucose molecule to two molecules of pyruvate and carbon dioxide. Glycolysis occurs in the mitochondria. It requires ATP and NADH. Glycolysis produces 30 ATP from each molecule of glucose.

It represents the first stage in the chemical oxidation of glucose by a cell.

According to the endosymbiont theory, which of the following organelles were once endosymbiotic prokaryotic organisms? Mitochondria and lysosomes Mitochondria and chloroplasts Chloroplasts and Golgi apparatus Golgi apparatus and ribosomes Ribosomes and lysosomes

Mitochondria and chloroplasts

Which of the following statements describes NAD+? NAD+ has more chemical energy than NADH. NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. NAD+ can donate electrons for use in oxidative phosphorylation. NAD+ is oxidized by the action of hydrogenases. In the absence of NAD+, glycolysis can still function.

NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.

In addition to ATP, what are the end products of glycolysis?

NADH and pyruvate

Which of the following statements about the chemiosmotic synthesis of ATP is correct? The energy for production of ATP from ADP comes directly from a gradient of electrons across the inner mitochondrial membrane. Oxygen participates directly in the reaction that makes ATP from ADP and P. The chemiosmotic synthesis of ATP requires that the electron transport in the inner mitochondrial membrane be coupled to proton transport across the same membrane. The chemiosmotic synthesis of ATP occurs only in eukaryotic cells, because it occurs in mitochondria. Chemiosmotic ATP synthesis requires oxygen.

The chemiosmotic synthesis of ATP requires that the electron transport in the inner mitochondrial membrane be coupled to proton transport across the same membrane.

Which statement about the citric acid cycle is correct? The citric acid cycle depends on the availability of NAD+, which is a product of glycolysis. The citric acid cycle produces most of the ATP that is subsequently used by the electron transport chain. The oxidation of compounds by the citric acid cycle requires molecular oxygen. The citric acid cycle oxidizes glucose to carbon dioxide. The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.

The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.

The oxygen consumed during cellular respiration is involved directly in which process or event?

accepting electrons at the end of the electron transport chain

What is the term for metabolic pathways that release stored energy by breaking down complex molecules?

catabolic pathways

Where does glycolysis take place in eukaryotic cells?

cytosol

Which of the following is NOT a product of photosynthesis? a) glucose b) oxygen c) sugars d) carbon dioxide e) None of the above; all are products of photosynthesis.

d) carbon dioxide

Enzymes responsible for biosynthesis of lipids would be located in what part of the cell?

endoplasmic reticulum.

Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?

glycolysis

Where does the Calvin cycle take place?

in the stroma of the chloroplast

where does oxidative phosphorylation occur?

inner mitochondrial membrane

During cellular respiration, acetyl CoA accumulates in which location?

mitochondrial matrix

where does acetyl CoA formation occur?

mitochondrial matrix

where does the citric acid cycle take place?

mitochondrial matrix

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

reduced.

During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is

retained in the two pyruvates.

In mitochondrial electron transport, what is the direct role of O2?

to function as the final electron acceptor in the electron transport chain

Which of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration? transforming the energy in glucose and related molecules in a chemical form that cells can use for work catabolism of sugars and related compounds producing complex molecules from chemical building blocks breaking down ATP, so that ADP and P can be reused the breakdown of glucose to carbon dioxide and water

transforming the energy in glucose and related molecules in a chemical form that cells can use for work

In glycolysis, for each molecule of glucose oxidized to pyruvate

two molecules of ATP are used and four molecules of ATP are produced

The electrons stripped from glucose in cellular respiration end up in which compound?

water