11 Ap Bio Ch. 6-8

Front 1

first law of thermodynamics

Back 1

the total amount of energy in the universe remains constant
energy cannot be created or destroyed; it can only be converted from one form to another

Front 2

What are the four types of energy?

Back 2

potential, kinetic, chemical, and heat/thermal energy

Front 3

For what three kinds of work do cells use energy?

Back 3

chemical work - to stockpile, build, rearrange, and break apart substances
mechanical work - to move flagella and other cell structures and (in multi-celled species) the whole body or portions of it
electrochemical work - to move charged substances into or out of the cytoplasm or an organelle compartment

Front 4

entropy

Back 4

a measure of the degree of a system's disorder
-everything will eventually crumble and die

Front 5

second law of thermodynamics

Back 5

a law of nature stating that the spontaneous direction of energy flow is from organized (usable) forms to less organized (unusable) forms; with each conversion, some energy is randomly dispersed in a form (usually heat) not as useful for doing work

Overall, energy flows in one direction.

Front 6

Energy changes in living cells tend to proceed spontaneously in the direction that results in a _______ in usable energy.

increase or decrease?

Back 6

decrease

Front 7

endergonic reaction

Back 7

e.g. in photosynthetic cells, energy inputs from the sun drive reactions that make glucose, the result being a net increase in usable energy
we say the reaction sequence is endergonic (meaning energy in)

Front 8

exergonic reaction

Back 8

reaction from "top of the energy hill" to the "base"
energetically, the downhill run is favored; it will proceed on its own and end w/ a net loss in energy
we say the reaction sequence is exergonic (meaning energy out)

Front 9

structure of ATP (adenosine triphosphate)

Back 9

nucleotide: covalent bonds join the five-carbon sugar ribose, the nucleotide base adenine, and three phosphate groups

Front 10

What is phosphorylation?

Back 10

hundreds of diff. enzymes can split off the outer phosphate group and join it to another molecule, which thus becomes primed to enter a reaction
=phosphate group transfer

Front 11

Phosphorylation (getting rid of a phosphate group) produces what?

Back 11

ADP (adenosine diphosphate) and a free inorganic phosphate atom (Pi)

Front 12

After phosphorylation, ADP can be converted back to ATP when an enzyme attaches inorganic phosphate (or a phosphate group derived from some other molecule) to it
-regenerating ATP this way is important aspect of __________
This circle of events is called: _________

Back 12

metabolism
ATP/ADP cycle

Front 13

Oxidation is:

Back 13

when a molecule loses one or more electrons

Front 14

Reduction is:

Back 14

when a molecule gains one or more electrons

Front 15

Oxidation and reduction are central to the formation of _____ during photsynthesis and aerobic respiration.

Back 15

ATP

Front 16

reactants

Back 16

substances that enter a reaction

Front 17

intermediates

Back 17

substances that form during a reaction (or a sequence of reactions)

Front 18

products

Back 18

substances left at the end of a reaction

Front 19

energy carriers

Back 19

activate enzymes and other molecules by phosphate-group transfers

mainly ATP

Front 20

cofactors

Back 20

assist enzymes by picking up electrons, atoms, or functional groups from a reaction site and giving them up at diff. sites

Front 21

What are four features of enzymes?

Back 21

1. speed up reactions
2. can be reused
3. can recognize both reactants and products in order to catalyze a reaction in both directions
4. very selective about the substances to which they will bind and thereby bring about change

Front 22

What 3 events occur in light-dependent reactions?

Back 22

1. pigments absorb sunlight energy and give up excited electrons
2. electron and hydrogen transfers lead to ATP and NADPH formation
3. the pigments that gave up the electrons in the first place get electron replacements

Front 23

What happens in the cyclic pathway of ATP formation?

Back 23

excited electrons leave the P700 reaction center, pass through an electron transport system, and then return to the original photosystem I
-electron flow drives ATP formation
-no NADPH is formed

Front 24

What happens in the noncyclic pathway of ATP formation?

Back 24

-transfers electrons through two photosystems and two electron transport systems in the thylakoid membranes
-begins when the chlorophyll P680 in photosystem II absorbs energy
1)boosted electron moves through a transport system that releases energy for ADP + Pi ==== ATP
2) electron fills "hole" left by electron boost in P700 of photosystem I
3) electron from photolysis (splitting) of water fills "electron hole" left in P680 and produces oxygen byproduct
-pathway continues when chlorophyll P700 in photosystem I absorbs energy
1)energy hole is filled by electron from P680
2)boosted electron P700 passes to acceptor, then ETS; it finally joins NADP to form NADPH (which along w/ ATP can be used in synthesis of organic compounds)

Front 25

Explain the chemiosmotic model of ATP formation.

Back 25

1) hydrogen ions from photolysis of water accumulate inside the thylakoid compartment of chloroplasts to set up concentration and electric gradients
2) oxygen atoms from photolysis combine to form O2 which is released into the atmosphere
3) as the hydrogen ions flow out through channels into the stroma, enzyme action links Pi to ADP to form ATP

Front 26

Which of the following would NOT be true of CAM plants?
a. fix carbon only once
b. live in desert environments
c. fix carbon mostly during the day
d. open stomata only at night
e. grow slowly

Back 26

c. fix carbon mostly during the day

Front 27

If one continues to increase the temperature in an enzyme-catalyzed reaction, the rate of the reaction:
a. does not change
b. increases and then levels off.
c. decreases and then levels off.
d. increases and then decreases rapidly.
e. decreases and then increases rapidly.

Back 27

d. increases and then decreases rapidly

Front 28

During chemiosmosis, ________ are transferred from NADH and FADH2 to electron acceptor molecules; and the energy released is used to create a(n) ____________ gradient across the inner mitochondrial membrane.

Back 28

electrons; proton

Front 29

In C4 plants, reactions that fix CO2 into four-carbon compounds occur in:

Back 29

mesophyll cells

Front 30

Select the process that are matched with the INCORRECT amount of ATP produced by that process per glucose molecule.
a.glycolysis-2 ATP(net)
b.citric acid cycle-4 ATP
c.electron transport chain-34(max)ATP
d.alcohol fermentation-2 ATP(net)
e.lactate fermentation-2 ATP(net)

Back 30

b.citric acid cycle-4 ATP

Front 31

In photosynthesis, ATP and NADPH are produced during:

Back 31

the light-dependent phase

Front 32

Considering only glycolysis and the conversion of pyruvate molecules to acetyl CoA molecules, how many NADH molecules will be produced from one glucose molecule?

Back 32

4

Front 33

The electrons lost by the P680 reactive center are replaced by electrons from:

Back 33

a water molecule

Front 34

The most important photosynthetic pigment is:

Back 34

chlorophyll a

Front 35

Parts of the enzyme molecule that interact with a substrate are called:

Back 35

active sites

Front 36

How many electrons are needed to reduce one molecule of NADP+ to NADPH?

Back 36

2

Front 37

The production of alcohol or lactate from pyruvate during __________ occurs as a means of regenerating ___________ from __________.

Back 37

fermentation; NAD+; NADH

Front 38

What are the reactants of the Calvin-Benson cycle?

Back 38

CO2, ATP, AND NADPH

Front 39

Which process does not match the products shown?
a.electron transport and chemiosmosis-ATP, H2O, NAD+
b.citric acid cycle-CO2, NADH, FADH2, ATP
c.formation of acetyl CoA-Acetyl CoA, CO2, NADH
d.glycolysis-pyruvate, ATP, NADH
e.All of the processes match the products.

Back 39

e. All of the processes match the products.

Front 40

According the chemiosmotic theory, concentration and electric gradients drive the formation of ____.

Back 40

ATP

Front 41

Because of its location in the electron transfer chain, delivery of electrons to each FAD results in how many ATPs?

Back 41

2

Front 42

Name this process.

This leads to the formation of glucose-6-phosphate (sugar phosphate) from 2 molecules of phosphoglyceraldehyde.

Back 42

Calvin-Benson cycle

Front 43

Name this process.

In this process carbon dioxide is incorporated first into an unstable intermediate compound and then into phosphoglycerate.

Back 43

carbon dioxide fixation

Front 44

Name this process.

This yields NADPH as well as ATP.

Back 44

light-dependent reactions

Front 45

Name this process.

This is a carbon-fixing system that precedes the Calvin-Benson cycle in some plants.

Back 45

C4 pathway

Front 46

Name this process.

PGAL molecules are formed from the reaction of PGA molecules with ATP and NADPH in this pathway.

Back 46

Calvin-Benson cycle

Front 47

Name this process.

produces NADH and CO2; changes pyruvate

Back 47

acetyl-CoA formation

Front 48

Name this process.

produces ATP, NADH, and CO2

Back 48

the Krebs cycle

Front 49

Name this process.

splits glucose into 2 pyruvate molecules

Back 49

glycolysis

Front 50

Name this process.

regenerates NAD+ as pyruvate; is converted to ethanol or lactate

Back 50

fermentation

Front 51

What process precedes (comes before) the Krebs cycle?

Back 51

glycolysis

Front 52

The generation of concentration gradients across mitochondrial membranes is called ____________.
a.chemiosmosis
b.ATP synthesis
c.electron transport chain
d.aerobic respiration

Back 52

a.chemiosmosis

Front 53

Which components, structures, or processes of photosynthesis is associated with light-independent reactions (dark reactions)?
A.Chemiosmosis
B.Photosystem I and II
C.The Calvin-Benson cycle
D.Photolysis
E.Breakdown of glucose to two molecules of pyruvate

Back 53

C.The Calvin-Benson cycle

Front 54

What happens during the TCA (Krebs) cycle?
I. Pyruvate is eventually oxidized to CO2.
II. Electrons and protons (H+ ions) are transferred to NAD+ and FAD+.
III. Oxygen serves as the final electron acceptor.
A.I only
B.II only
C.III only
D.I and II only
E.I, II, and III

Back 54

D.I and II only

Front 55

Which statement(s) about glycolysis is(are) correct?
I. A steady supply of NAD+ is needed.
II. An ATP molecule is needed to begin the pathway.
III. PGAL is converted to pyruvate through a reduction reaction.
A.I only
B.II only
C.III only
D.I and II only
E.I, II, and III

Back 55

D.I and II only

Front 56

How do inhibitors of enzyme-catalyzed reactions work?
A.They bind to the enzyme active site.
B.They tie up the molecule of ATP to prevent a coupled reaction.
C.They use up all of the reactants.

Back 56

A.They bind to the enzyme active site.

Front 57

In plant cells undergoing photosynthesis, what kind of chemical reaction produces ATP from ADP and inorganic phosphate?
A.Coenzyme activation
B.Oxidation
C.Reduction
D.Hydrolysis
E.Phosphorylation

Back 57

E.Phosphorylation

Front 58

Which statement(s) about endergonic reactions is(are) true?
I. They have a negative G.
II. They are nonspontaneous.
III. The products of the reaction have more free energy than the reactants.
A.I only
B.II only
C.III only
D.II and III only
E.I, II, and III

Back 58

D.II and III only

Front 59

__________ plays no role in glycolysis.

Back 59

oxygen

Front 60

Which of the following processes occurs in both respiration and photosynthesis?
a. chemiosmosis
b. calvin cycle
c. citric acid cycle
d. krebs cycle
e. glycolysis

Back 60

a. chemiosmosis

Front 61

Which of the following statements is INcorrect?
a.glycolysis can occur w/ or w/o oxygen
b.glycolysis occurs in the mitochondria
c.glycolysis is the first step in both anaerobic and aerobic respiration
d.glycolysis leads to production of 2ATP, 2NADH, and 2 pyruvate

Back 61

b. glycolysis occurs in mitochondria
*glycolysis occurs in CYTOPLASM