Biology Test 2, Chapter 6

Front 1

Cellular Respiration

Back 1

what cells do to break up sugars into a form that the cell can use as energy. This happens in all forms of life. Cellular respiration takes in food and uses it to create ATP, a chemical which the cell uses for energy.

Front 2

What is misleading about this statement? "Cells perform photosynthesis, and animal cells perform cellular respiration."

Back 2

The statement implies that cellular respiration does not occur in plant cells. Almost eukaryotic cells use cellular respiration to obtain energy.

Front 3

How is your breathing related to your cellular respiration?

Back 3

Your lungs absorb O2, your cells then use the O2 for cellular respiration and expel CO2 as a waste through exhaling.

Front 4

Why are sweating and other body-cooling mechanisms necessary during rigorous exercise?

Back 4

When you exercise, you are burning large amounts of ATP, burning ATP creates heat. We need to maintain our temperature in order to not overheat.

Front 5

Walking at 3mph, how far would you have to travel to burn off 475 kcal?

Back 5

6 miles

Front 6

Kilocalories (kcal)

Back 6

a quantity of heat equal to 1,000 calories. Used to measure the energy content of food.

Front 7

redox reaction

Back 7

short for reduction-oxidation reaction; a chemical reaction in which electrons are lost from one substance (oxidation) and added to another(reduction).

Front 8

oxidation

Back 8

The loss of electrons from a substance involved in a redox reaction; always accompanies reduction.

Front 9

reduction

Back 9

The gain of electrons by a substance involved in a redox reaction; always accompanies oxidation.

Front 10

NAD+

Back 10

Nicotinamide Adenine Dinucleotide; a coenzyme that can accept electrons during the redox reactions of cellular metabolism.

Front 11

Electron transport chain

Back 11

A series of electron carrier molecules that shuttle electrons during a series of redox reactions that release energy used to make ATP; located in the inner membrane of mitochondria, the thylakoid membranes of chloroplasts, and the plasma membranes of prokaryotes.

Front 12

Stage 1 of cellular respiration: Glycolysis

Back 12

A series of reactions that ultimately splits glucose into two molecules of pyruvate; the first stage of cellular respiration.

Front 13

Stage 2 of cellular respiration: Citric Acid Cycle

Back 13

The chemical cycle that competes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA to carbon dioxide. The cycle occurs in the Mitochonrial Matrix and supplies NADH molecules to electron transport chains. Second major stage of cellular respiration.

Front 14

Stage 3 of cellular respiration: Oxidative Phosphorylation

Back 14

The production of ATP using energy derived from the redox reactions of an electron trasport chain; the third major stage of cellular respiration.

Front 15

chemiosmosis

Back 15

an energy-coupling mechanism that uses the energy of hydrogen ion (H+) gradients across membranes to drive cellular work. powers most ATP synthesis in cells.

Front 16

susbtrate-level phosphorylation

Back 16

The formation of ATP by an enzyme directly transferring a phosphate group to ADP from an organic molecule.

Front 17

intermidiates

Back 17

one of the compounds that form between the initial reactant and the final product in a metabolic pathway, such as between glucose and pyruvate in glycolysis.

Front 18

acetyl CoA

Back 18

(acetyl coenzyme A) the entry compound for the citric acid cycle in cellular respiration; formed from a two-carbon fragment of pyruvate attached to a coenzyme.

Front 19

ATP synthase

Back 19

A cluster of several membrane proteins that function in chemiosmosis with adjacent electron transport chains, using the enrgy of a hydrogen ion concentration gradient to malke ATP.

Front 20

lactic acid fermentation

Back 20

Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD+

Front 21

alcohol fermentation

Back 21

Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide.

Front 22

What chemical characteristic of the element oxygen accounts for its function in cellular respiration?

Back 22

Oxygen is extremely electronegative, making it very powerful in pulling electrons down the electron transport chain.

Front 23

of the three main stages of cellular respiration, which is the only one that uses oxygen?

Back 23

Oxidative phosphorylation, in which the electron transport chain ultimately transfers electrons to oxygen.

Front 24

Two molecules of pyruvate, two molecules of ATP, and two molecules of NADH.

Back 24

For each molecule processed, what are the net molecular products of glycolysis?

Front 25

What is the total number of NADH and FADH2 molecules generated during the complete breakdown of one glucose molecule to six molecules of CO2?

Back 25

10 NADH: 2 molecules of glycolysis; 2 from the oxidation of pyruvate; 6 from the citric acid cycle; and 2 FADH2 from the citric acid cycle.

Front 26

Explain where O2 is used and CO2 is produced in cellular respiration.

Back 26

O2 accepts electrons at the end of the electron transport chain. CO2 is released during the oxidation of intermediate compounds in pyruvate oxidation and the citric acid cycle.

Front 27

A glucose-fed yeast cell is moved from an aerobic environment to an anaerobicone. For the cell to continue generating ATP at the same rate, how would its rate of glucose consumption need to change?

Back 27

The cell would have to consume glucose at a rate about 16 times the consumption rate in an aerobic environment (2 ATP per glucose molecule is made by fermentation, versus 32 ATP by cellular respiration).

Front 28

List some of the characteristics of glycolysis that indicate that it is an ancient metabolic pathway.

Back 28

Glycolysis occurs universally (functioning in both fermentation and respiration), does not require oxygen, and does not occur in a membrane-enclosed organelle.

Front 29

Animal store most of their energy reserves as fats, not as polysaccharides. What is the advantage of this mode of storage for an animal.

Back 29

most animals are mobile and benefit from a compact and concentrated form of energy storage. Also, because fats are hydrophobic, they can be stored without extra water.

Front 30

Explain how someone can gain weight and store fat even when on a low-fat diet.

Back 30

If caloric intake is excessive, body cells use metabolic pathways to convert the excess to fat. You don't need to eat fats to make fats.