4: Flow of Matter and Energy in Cells

Question 1

What is Cellular Metabolism

Answer 1

chemical processes that sustain plant or animal life

Question 2

What is special about most of life-sustaining chemical reactions?

Answer 2

Most are enzyme catalyzed

Question 3

What does ∆G < 0 mean?

Answer 3

Reaction is spontaneous

Question 4

How does an enzyme affect activation energy?

Answer 4

Lowers it, thus speeding up reactions

Question 5

What is a metabolic pathway made up of?

Answer 5

enzyme-catalyzed reactions

Question 6

What is a catabolic reaction?

Answer 6

nutrient degradation (oxidation), produce ATP

Question 7

What is an anabolic reaction

Answer 7

biosynthesis (reduction), requires/uses ATP

Question 8

What are amphibolic pathways

Answer 8

Pathways that do both catabolism and anabolism

Question 9

Which pathways are thermodynamically unfavorable coupled to favorable reactions?

Answer 9

Anabolic reactions

Question 10

What is the most activated carrier molecule

Answer 10

ATP

Question 11

Is a healthy cell at equilibrium?

Answer 11

NOOOOO

Question 12

What is energy from ATP usually used for?

Answer 12

To join two molecules together

Question 13

What are two other energy electron carriers besides ATP

Answer 13

NADH and NADPH

Question 14

What is the function of NADH?

Answer 14

-Primarily involved in catabolic reactions
-Is an electron carrier in the reactions as it accepts electrons from substrates during oxidation.
-Electrons carried by NADH are passed through ETC in mitochondria which generates a proton gradient.

Question 15

What are the main functions of NADPH?

Answer 15

-Primarily involed in anabolic reactions which require energy
-It’s a reducing agent providing reducing power in form of electrons and protons for various biosynthetic pathways
-Essential for redox reactions

Question 16

What is the main source of fuel to cells?

Answer 16

Glucose

Question 17

What is glucose broken down into?

Answer 17

CO2 and H2O and the released energy is captured by ATP and NADPH

Question 18

What is stepwise oxidation?

Answer 18

Small activation energies that don’t burn everything all at once.

Question 19

What converts glucose to pyruvate and how?

Answer 19

Glycolysis anaerobically

Question 20

What are the three stages of glucose catabolism?

Answer 20

Investment, Cleavage, Energy Harvest.

Question 21

Does glycolyisis produce ATP without O2?

Answer 21

NO

Question 22

what cellular process is used by nearly all organisms on this planet?

Answer 22

Glycolysis

Question 23

What stage converts glucose to an unstable, high energy intermediate?

Answer 23

The energy investment stage

Question 24

What does the cleavage stage of glucose catabolism produce?

Answer 24

Two 3-carbon sugars

Question 25

How much energy does the investment stage use?

Answer 25

2 ATP molecules

Question 26

What does the energy harvest stage do in glycolysis?

Answer 26

Turns the three carbon sugars from the cleavage stage to 2x pyruvate. Harvests 2 NADH & 2 ATP

Question 27

What does glycolysis of 1 glucose result in?

Answer 27

2 Pyruvate, 2 ATP, 2 NADH

Question 28

Is glycolysis with or without oxygen?

Answer 28

Without

Question 29

What cycle harvests energy from pyruvate in the mitochondria?

Answer 29

Krebs Cycle/ Tricarboxylic acid Cycle (TCA)

Question 30

What does pyruvate react with to produce acetyl-coA?

Answer 30

Co-enzyme A

Question 31

What does Acetyl-coA produce?

Answer 31

One CO2 and One NADH

Question 32

Other than by the reaction with pyruvate, how else can acetyl CoA be produced?

Answer 32

From Breakdown of fats or amino acids

Question 33

What does the Krebs cycle release?

Answer 33

CO2 as waste and NADH

Question 34

Does the TCA cycle need O2?

Answer 34

Not directly but needs it to run

Question 35

Where is the ETC?

Answer 35

in the inner membrane of the mitochondrion

Question 36

How are high energy electrons carried to the ETC?

Answer 36

NADH and FADH2

Question 37

How are protons moved to the ETC

Answer 37

coupled redox reactions bring high energy protons with the NADH and FADH2 transferred

Question 38

How many protons are transferred with each pair of electrons from NADH

Answer 38

4 protons

Question 39

How is energy stored in the ETC

Answer 39

In the form of a proton gradient

Question 40

How is ATP synthase powered to make ATP?

Answer 40

By the proton gradient