Chapter 6- Harvesting Cellular Energy

Question 1

A molecule is oxidized when what happens to it?

Answer 1

When it loses one or more electrons

Question 2

Reduction is ______.

Answer 2

The addition of electrons to a substance

Question 3

What occurs in cellular respiration?

Answer 3

02 is consumed as organic molecules are broken down to CO2 and H2O

The cell captures the energy released in ATP

Question 4

Photosynthesis occurs in chloroplasts of plants/algae and some ______.

Answer 4

Prokaryotes

Question 5

Cellular respiration occurs in the mitochondria of _____ and almost all _____.

Answer 5

Many prokaryotes

Almost all eukaryotes (plants, animals, fungi, and protists

Question 6

Matter is ______ but energy _____.

Answer 6

Recycle

Is not recycled

Question 7

Respiration refers to _____.

Answer 7

An exchange of gases

Question 8

Biologists also define respiration as _____.

Answer 8

The aerobic harvesting of energy from food molecules

Question 9

Cellular respiration harvests energy from _____ and _____.

Answer 9

Glucose

Other organic molecules

Question 10

In cellular respiration, O2 is used to _____.

Answer 10

Help cells breakdown glucose and other molecules to obtain ATP

Question 11

C6H12O6 + 6O2 ———> _______.

Answer 11

6CO2 + 6H2O + ATP + heat

Question 12

What do cells use most often for fuel?

Answer 12

Simple sugar, glucose

Question 13

In the Exergonic reaction of breaking down glucose, some of the energy released is stored as _____.

Answer 13

ATP

Question 14

How many ATP molecules are produced from each glucose molecule?

Answer 14

Up to 32 ATP molecules

Question 15

How much energy is captured from the breakdown of glucose?

Answer 15

About 34%

Question 16

What occurs to the rest of the energy released in the Exergonic reaction of cellular respiration?

Answer 16

It is lost as heat

Question 17

What helps maintain body temperature?

Answer 17

Heat released from cellular respiration

Question 18

The unit of measurement of energy is _____.

Answer 18

Kilocalories (kcal)

Question 19

The human brain consumes how much glucose per day for energy? This accounts for what % of the body’s total energy consumption?

Answer 19

120g

20%

Question 20

What is a kcal?

Answer 20

The quantity of heat required to raise the temperature by 1 degree Celsius

Question 21

How man jacks does the human body need?

Answer 21

1300-1800 kcal

Question 22

What is the basal metabolic rate? (BMR)

Answer 22

The energy requirement for the human body (1300-1800 kcal/day)

Question 23

The US National Academy of Science says the average human needs how many kcal per day?

Answer 23

2,200

Question 24

What affects your daily calorie intake?

Answer 24

Age, sex, activity level

Question 25

What is a redox reaction?

Answer 25

The transfer of electrons from one molecule to another | An oxidation-reduction reaction

Question 26

In a redox reaction, the loss of one or more electrons from a substance is called _____.

Answer 26

Oxidation

Question 27

In a redox reaction, the addition of electrons to another substance is called _____.

Answer 27

Reduction

Question 28

What is the important coenzyme used in oxidizing glucose?

Answer 28

The enzyme NAD+ (nicotinamide adenine dinucleotide

Question 29

What does NAD+ do?

Answer 29

It accepts electrons, becoming REDUCED (reduction: adding electrons to a substance) Shuttles electrons

Question 30

An enzyme called ______ strips _____ from the organic ______.

Answer 30

Dehydrogenase Two hydrogen atoms Food molecule

Question 31

Once hydrogenase removes 2 hydrogen atoms from the food molecule, what does it do?

Answer 31

Hydrogenase transfers two electrons and one proton to NAD+, reducing it to NADH. The second proton is released into the surrounding solution.

Question 32

Once NAD+ is reduced to NADH, it carries the electrons and drops them off at the _______.

Answer 32

Electron transport chain

Question 33

The electron transport chain is composed of what?

Answer 33

Carrier molecules (mostly all proteins)

Question 34

At the end of the electron transport chain, what occurs?

Answer 34

An oxygen atom accepts two electrons, picks up 2H+, and is REDUCED to H2O

Question 35

What is released through the electron transport chain?

Answer 35

Controlled release of energy for ATP synthesis

Question 36

Glycolysis is the process of _____.

Answer 36

Oxidizing glucose through redox reactions (?)

Question 37

What are the 3 stages of cellular respiration?

Answer 37

1. Glycolysis 2. Pyruvate oxidation and citric acid cycle 3. Oxidative phosphorylation

Question 38

Glycolysis basically does what?

Answer 38

Splits glucose into two molecules of a three carbon compound called pyruvate

Question 39

What is pyruvate?

Answer 39

The product of glycolysis, glucose broken down to form two molecules of a 3 carbon chain compound

Question 40

Where do pyruvate oxidation and the citric acid cycle take place?

Answer 40

Within the mitochondria

Question 41

What does the citric acid cycle do?

Answer 41

Breaks down the rest of glucose, after pyruvate oxidation, to CO2

Question 42

In the _____ stage of cellular respiration, CO2 is formed through the _____ cycle in the _____.

Answer 42

Second Citric acid cycle (process of breaking down glucose to form CO2) Mitochondria

Question 43

What occurs to pyruvate exiting glycolysis, once it enters the mitochondria?

Answer 43

It is oxidized to a two carbon compound after which the citric acid cycle takes over

Question 44

A small amount of _____ produced during _____ and _____.

Answer 44

ATP Glycolysis Citric acid cycle

Question 45

A cell produces most of it’s _____ during _____.

Answer 45

Oxidative phosphorylation

Question 46

What is oxidative phosphorylation?

Answer 46

Occurring after the citric acid cycle, electrons are transported to an electron transport chain embedded in the inner mitochondrial membrane. Oxidative phosphorylation captures the energy of the redox reactions occurring once NADH and FADH carry electrons to the inner mitochondrial membrane. The electrons are eventually dropped off at O2, where two H+ atoms joins to form water.

Question 47

During oxidative phosphorylation, what does the electron transport chain ALSO do?

Answer 47

Pumps H+ ions across the intermembrane space resulting in a high concentration of H+ ions

Question 48

What is chemicals?

Answer 48

Creating ATP from the H+ rich concentration within the mitochondrial intermembrane space.

Question 49

Pyruvate itself does/does not enter the citric acid cycle?

Answer 49

Does not

Question 50

What actually enters the Citric Acid cycle (Krebs cycle)?

Answer 50

Two molecules of acetyl CoA

Question 51

How is pyruvate prepared to enter the Krebs cycle?

Answer 51

A carboxyl group (—COO-) is removed and given of as CO2 The two carbon pyruvate is oxidized A molecule of NAD+ is reduced to NADH The two carbon group then joins with a compound, coenzyme A (CoA), to form acetyl coenzyme A (acetyl CoA)