Exam #3 Flashcards Preview

BSC 2010 - Biology I > Exam #3 > Flashcards

Flashcards in Exam #3 Deck (205):
1

This chapter is about one thing...it's about how cells make ___.

ATP

2

Most life on earth acquires energy through ___________, followed by ________ _________.

photosynthesis, cellular respiration

3

Our energy comes from the sun. It is harnessed by plants. The chloroplast converts that light energy into _______ energy, in the form of organic molecules.
Photosynthesis requires some starting material, and that would be ___ and ____.

chemical
CO2 and H20

4

What is the most efficient way to do catabolism?

Respiration

5

Cellular respiration is a ________ breakdown

complete

6

Fermentation is an ________ breakdown

incomplete

7

The whole point of catabolism is to provide ________ for the manufacturing of ATP. ALL ABOUT MAKING ATP

energy

8

Organic fuel is oxidized, what does that mean?

It means the removal of electrons

9

If something is oxidized, it's _______ its electrons.

losing

10

Reduction is the ______ of electrons

gain

11

If something is oxidized and loses its electrons, something else is reduced and _____ those electrons

gains

12

What kind of bond does CH4 have?

non-polar covalent bond

13

What does non-polar covalent bond mean, in terms of electrons?

Electrons are all shared equally

14

What kind of bond does CO2 have?

polar-covalent bond

15

What does polar covalent bond mean, in terms of electrons?

Electrons are not shared equally, oxygen is pulling on the electrons

16

Rule of thumb: watch the ________ !

HYDROGENS!

17

Electrons are transferred along with protons...what is a proton? A hydrogen atom. So if we're transferring protons, we're transferring hydrogens. Does Carbon gain or lose hydrogen's in this reaction?

It lost all of them

18

Does the oxygen gain or lose hydrogens in the reaction?

It gained them, which means reduction

19

If you lose hydrogens, you're ________
If you gain hydrogens, you're ________

oxidized
reduced

20

It's the _______ in methane that have the energy

electrons

21

In non-polar covalent bonds, electrons are ____ from the nucleus and have more energy

far

22

In polar covalent bonds, electrons are _____ to the nucleus and have less energy

close

23

What about electrons in glucose? Energy poor or energy rich?

Energy rich, non-polar covalent bonds

24

Glucose and fats are biologicals fuels...we consume them and drain them of their energy...BY WHAT?

OXIDATION. It's the electrons that have the energy, we're going to oxidize the heck out of them, get all those electrons!

25

This is the reaction that attaches an inorganic phosphate to ADP to make ATP. This is called _________.

phosphorylation

26

When you join a phosphate to something, it's called __________.

phosphorylation

27

ATP synthesis is _________.

Endergonic

28

What is the equation or "process" for cellular respiration?

C6H12O6 + 6O2 --> 6CO2 + 6 H20 + energy (ATP+heat)

29

What is the delta G for cellular respiration?

Delta G = -686 kcal/mole

30

How much energy is released when glucose is catabolized?

-686 kcal/mole

31

How does aerobic glucose catabolism compare with processes like the combustion of methane? How is it different?

They're similar in that, glucose catabolism and combustion of methane are both...
Exergonic...
Organic fuel is oxidized (CH4 and C6H12O6)...
And oxygen is the oxidizing agent.
That said, this is not combustion. It's not even a single reaction. Glucose catabolism is a process.
Also, unlike the combustion of methane, glucose catabolism is going to have many reactions. Steps. Glucose catabolism.

32

The words electrons and ________ are used interchangeably

hydrogens

33

H's are eventually transferred to O2, but are FIRST transferred to chemicals known as _________, which will hold them for a time...hold them...

coenzymes

34

What are coenzymes?

Small molecules required by some enzymes.

35

Are coenzymes enzymes?

NO, THEY ARE NOT ENZYMES

36

Coenzymes are like a substrate of an enzyme. They will _____ to the enzyme. Like the substrate, they will be chemically _______ in the reaction.

bind, altered

37

Coenzymes have a very specific purpose, which is to serve as a molecular _____.

handle

38

Why are we taking the H's from glucose?

They have ENERGY!

39

You take the H, you don't want to lose track of the H...it's so small...you need to chemically/covalently attach it to something that can serve as a _____ to carry the H to where it can be utilized for its energy content.

handle

40

What are three common coenzymes?

NAD+, FAD, Coenzyme A

41

Which of the three doesn't carry H?

Coenzyme A

42

What is the main coenzyme?

NAD+

43

To be more specific, NAD+ carries one complete __ and one ______.

hydrogen, electron

44

EXAM QUESTION:
When NAD+ is reduced, what does it carry?

2e- and 1 p+

45

What is the reduced form of NAD+?

NADH

46

What is the difference between NAD+ and NADH?

The H, which is one electron and one proton.

47

Where is the other electron? Ah, there's a charge...a charge where?

NAD+

48

NAD+ is an electron carrier that keeps the electrons _______.

energetic

49

How much energy is lost as we transfer electrons from glucose to NAD+?

Very little energy is lost

50

What is NAD+ specifically?

Two nucleotides join together...
Nicotinamide adenine dinucleotide

51

In NAD+, the two nucleotides are joined together by their __________.

phosphates

52

What's important about NAD+?

It carries hydrogens

53

What kind of agent is NAD+?

Oxidizing agent

54

If you have a chemical with H's, you can strip them away with _____.

NAD+

55

**Once NAD+ strips away the H's, that chemical is ________, and NAD+ is _________.

oxidized, reduced

56

NAD+ does not carry both protons...it carries two ______ and one ______. So the other proton from that H goes into the _______.

two electrons, one proton.
solution

57

Start out with NAD+...NAD+ is _______...it delivers its electrons...NADH is ______.
NAD+ is _______, then NADH is ______...it goes back and forth

reduced, oxidized
reduce, oxidized

58

Who is the ultimate electron acceptor?

Oxygen

59

Who is the ultimate oxidizing agent?

Oxygen

60

EXAM QUESTION:
Who does NADH reduce?
Who does NADH give its electrons to?

**THE ELECTRON TRANSPORT CHAIN**

61

What are the four stages of cellular respiration?

Glycolysis
Pyruvate oxidation
Citric acid cycle
Electron transport chain

62

The first _____ stages of cellular respiration are going to catabolize glucose completely.

three. By the end of step 3, glucose will be completely catabolized.

63

Catabolism will occur through ________.

Oxidation

64

We're going to _______ in glycolysis.
We're going to _______ in pyruvate oxidation.
We're going to _______ in the citric acid cycle

OXIDIZE, OXIDIZE, OXIDZE.
***Stripping away electrons.***

65

Many NAD+ are going to be _______.
Many NADH's will be generated...

reduced

66

What happens in step 4? In step 4, _____ delivers those electrons to the....

NADH, electron transport chain.

67

When NADH delivers electrons to the ETC, NADH will become ________

oxidized, then back to NAD+

68

When do we make the ATP? Which stages?

1 and 3.
Literally Glycolysis and citric acid cycle

69

Which stage does not really make ATP?

Pyruvate oxidation

70

Which stage makes the most ATP?

Stage 4, ETC

71

It's all about transferring those electrons...
We ____ the electrons in stage 1, we ____ the electrons i stage 2, we ____ the electrons in stage 3, and then _______ the electrons in stage 4 and that's where ATP is finally made.

took, took, took, delivered

72

Where do these processes happen?
Cellular respiration beings in the _______. That's where glycolysis happens. The product of glycolysis is imported into the __________. Everything else happens in the mitochondria. Stage 2 - pyruvate oxidation, stage 3 - citric acid cycle, stage 4 - ETC. So most of these things happen in the mitochondria. Glycolysis happens in the cytosol.

cytosol. mitochondria.

73

What's the point of each stage? We're _______ the sugar, creating the _______ coenzyme _____.

oxidizing, reduced, NADH

74

90% of ATP is made in stage __.

4

75

Glycolysis is a __ step pathway.

10

76

Glycolysis is run by __ enzymes.

10

77

Glycolysis means "sweet split." The splitting of a sugar molecule. Glycolysis breaks glucose into __ smaller molecules.

2

78

In step 1, glucose is converted into the first _______ of glycolysis

intermediate

79

What is the other reactant, in addition to glucose, in this reaction?

ATP

80

What's the other product?

ADP

81

So ATP was hydrolyzed. It's phosphate was removed. Notice that the phosphate has become part of the glucose.
By burning and ATP to make the phosphate there, we're making the sugar even more _______.

reactive. Even more energy rich...it's got a phosphate now

82

Step 2 is a _________. Or isomerization.

Rearrangement. It rearranges the atoms and the sugar.

83

Step 3, something familiar happens...what? Another ATP is invested...to make our sugar even more _______. It's got another phosphate now! It's now got 2 phosphates! Even more ______!

reactive, reactive!

84

Step 3 is the first step I would like you to know specifically...
EXAM:
***Step 3 is catalyzed by the enzyme ______________.***

Phosphofructokinase (PFK)

85

What enzyme catalyzes step 3?

PFK

86

Through___, we control a large part of cellular respiration.

PFK

87

Step 4 _____ the sugar.

splits. glucose has 6 carbons, so it's split right down the middle, 3 carbons and 3 carbons.

88

EXAM QUESTION:
In stage 4, the sugar is split into 2 smaller sugars, which are ___ and ___.

DHP and G3P

89

Step 5 converts ___ into a second ___

DHP into a second G3P

90

We now have two ____.

G3P's

91

From from here to the rest of catabolism, everything is going to happen ______.

twice

92

Everything happens twice now because we ....?

Split the sugar

93

**What happens in step 6?**

It's an oxidation reaction! It's the first one! IT HAPPENS IN STEP 6!!!

94

Which step has the first oxidation reaction?

Step 6.

95

In step 6, G3P is ________ by NAD+, generating _____.

oxidized, NADH

96

What does step 7 do, finally?

Makes ATP

97

Which step in glycolysis is ATP first made in cellular respiration?

STEP 7!

98

How many NADH do we have and why?

2 NADH because we have 2 G3P

99

How many ATP do we make?

2! Everything happens twice

100

What happens in step 10?

2 more ATP is made

101

What is the final product in glycolysis?

Pyruvate

102

Glycolysis is split into 5 and 5. Recognize that the first half, we invested some _____. The second half, we saw the payoff into the form of ___.

energy, ATP

103

How many NADH were produced in glycolysis and in what step?

2 NADH were produced, in step 6

104

ATP was made twice! Once in step __ and once in step __

7 and 10

105

How much total ATP does glycolysis produce?

4

106

ATP synthesis is ________.

endergonic

107

Where did the energy come from?

The substrate

108

Enzymes don't change the _____ __, but they DO enable _______.

coupling

109

Substrate level phosphorylation: making ___ by transferring a ______ from an organic ______ to ___, which makes ATP.

ATP, phosphate, substrate ADP

110

This happened twice...twice in step _ and then twice in step _, which is the 4 ATP.

7 and 10

111

Glycolysis can be divided into two parts.
The first part of glycolysis deals with ________ energy, to make the sugar even more energetic and reactive.
The second part of glycolysis, really beginning in step 6, is an energy _______. When we use the invested energy to produce a product. To make ATP, step 7. To make ATP, step 10. And also, to make _____. PLEASE, THIS IS MORE IMPORTANT THAN THIS LITTLE AMOUNT OF ATP. This is more important because we've established that's the way we're going to strip electrons away from glucose, that's the way we're ultimately going to derive energy as ATP.

investing, payoff, NADH

112

At the end of glycolysis, how many pyruvate are produced?

2

113

In glycolysis, we make _ ATP.

4

114

_ ATP produced per G3P
_ ATP produced per glucose
****NET of _ ATP per glucose. ****

2
4
****2****

115

Why a net of 2 ATP per glucose?

We put in 2 ATP, so 4-2 = ***2***

116

_ NADH per glucose

2

117

The energy is coming from the sugar, to make ATP, to make ____

NADH

118

The final product of glycolysis, pyruvate, is transported to the _________ _____

mitocondrial matrix

119

Pyruvate oxidation is a _ step pathway, requiring _ enzymes.

3

120

The enzymes are bound to one another to form a multi-enzyme _______. This is a very efficient way to run a pathway.

complex

121

What is step 1?

Removing CO2 from pyruvate. CO2 is held together by polar covalent bonds. It has no energy. Get rid of it.

122

Where is the first CO2 of cellular respiration produced?

Step 1 of pyruvate oxidation

123

What is step 2?

Oxidation!
NAD+ is going to strip H's away from pyruvate and the result is NADH.

124

What is step 3?

Attaching what's left to a coenzyme
***So attaching an acetyl group to coenzyme A, you get a chemical called ***Acetyl Coenzyme A***

125

Pyruvate oxidation, tabulate per glucose...
_ CO2 have been made, of the 6
_ NADH have been made, which you can add to the two made from glycolysis (2)
_ Acetyl Coenzyme A have been made

2
2
2

126

The citric acid cycle is an _ step pathway, involving _ enzymes

8

127

It's a cycle, what does that mean?

One of the initial reactants is recycled at the end of the pathway

128

There are _ reactants in the first reaction

2

129

One of those reactants reappears....it's recycled at the end of the pathway...and so if you use it and produce it again...in effect, the pathway forms a _____.

cycle

130

This pathway ______ catabolizes the sugar

completely

131

The citric acid cycle is sometimes referred to as the ______ cycle

Krebs

132

The coenzyme A is holding the acetyl group and is now delivering it...who does it deliver it to?

Oxaloacetate

133

There are two reactants in this first reaction...
The first reactant is _______ _______ _, and the other is _________.

acetyl coenzyme A
Oxaloacetate

134

The coenzyme's job is done, so the coenzyme goes away, and the result is this chemical here...what is this chemical called?

Citrate...aka citric acid

135

The citric acid cycle is named for the first product of the pathway, which is _______.

citrate

136

How many CO2 are made per cycle? PER ONE CYCLE

2

137

How many NADH are made? PER ONE CYCLE
How many ATP are made? PER ONE CYCLE
How many FADH2 are made? PER ONE CYCLE

3
1
1

138

What is the most energy harvesting process in cellular respiration?

The citric acid cycle. You generate the most products

139

Is this single cycle tabulating back to our original glucose?
No! We have **2 acetyl coenzyme A**...that will complete this cycle. Everything happening here will happen **TWICE!
** Ohhh, so we made _ CO2!

4 CO2

140

We made _ CO2 in pyruvate oxidation, _ in citric acid cycle, that's 6 CO2! We're done with catabolism!
We made _ NADH! We made _ FADH2 and _ ATP

2, 4
6, 2, 2

141

Folks, we have now completely catabolized glucose.
Glucose has 6 carbons, all 6 have been realized as ___.

CO2

142

We've made _ ATP.
_ in glycolysis and _ in the citric acid cycle.

We've made 4 ATP
2 in glycolysis, 2 in the citric acid cycle

143

How much total NADH have we made?
_ in glycolysis, _ in pyruvate oxidation, _ in citric acid cycle.
How much total FADH2 have we made?

10
2, 2, 6
2

144

**EXAM, KNOW THIS**
I want you to know that pyruvate oxidation is an ________, so you make _____. It begins the production of ___, so you make CO2. And it produces a product of ______ _______ _, which carries the acetyl group into the citric acid cycle.

oxidation, NADH, CO2, acetyl coenzyme A

145

**EXAM, KNOW THIS**
I want you to know that the ______ _____ _____ completes catabolism and you make the remaining ___ there. The citric acid cycle oxidizes the heck out of the sugar in completing that catabolism. So you make _ NADH there, you make _ FADH2 there, you make _ ATP.

citric acid cycle, CO2
6, 2, 2

146

Most of the harvested energy in glucose is now in _____.

NADH

147

EXAM QUESTION:
NADH is now ________ by an electron transport chain

oxidized, passing on its electrons to the electron transport chain

148

The electron transport is a 'chain' of proteins within the _____ ________. These proteins are joined together to form ____ complexes.

inner membrane, four

149

Which protein is embedded in the inner membrane of the mitochondria?

ATP synthase

150

In order for the ATP synthase to produce ATP, its rotor has to rotate. That rotation causes a conformational change in this domain of the protein, which produces ____.

ATP.

151

The inner membrane is highly ______, that's where the ETC is.

folded

152

What does 'transport' mean? Electron 'transport'...

Electron transport means is simply that the chain is adapting to accepting electrons and then passing them along. That's what it does. If you give it electrons, it passes it along within the components of the transport chain.

153

The chain does _____.

redox

154

The chain is oxidized by _______.

oxygen

155

Where do the electrons go?

Oxygen

156

______ is the terminal electron acceptor.

Oxygen

157

In the fourth complex...
Oxygen + protons + electrons = ____

H20. That's the H20 that's produced in cellular respiration

158

For 1 NADH, _ electrons are carried
So for 1 NADH, you make _ H20

2
1

159

For 2 NADH, _ electrons are carried
So for 2 NADH, you make _ H20

4
2

160

What happens to the electrons energy over the course of this chain? Increases or decreases?

Decreases

161

Electronegativity _______ as you go down the chain

increases

162

How is ATP going to be generated?

In order to generate ATP, we need to turn the rotor on the ATP synthase

163

The chain proteins transport electrons, but that's a misnomer...when they do redox, they also harness the energy of the electrons passing through, and use that energy to move ______ across the inner membrane.

protons

164

They're moving protons across the inner membrane. What does that do? What happens if you keep moving protons from the matrix to the inner membrane space? If you're moving protons on one side of the membrane...you're creating a _______.

gradient

165

Gradients store ________! So the train transforms energy from electron energy into GRADIENT ENERGY in the form of a proton gradient.

Energy

166

***The chain proteins establish a ______ gradient, which stores energy! ***

proton

167

ATP synthase is also a proton ________.

channel

168

Cellular respiration is endergonic or exergonic?

exergonic

169

Using a proton gradient to make ATP is called ___________.

chemiosmosis

170

EXAM:
The process that makes ATP in stage 1 and 3 is called _______ ______ _________.

Substrate level phosphorylation.
The key is to recognize, what's the source of energy?

171

Making ATP is exergonic or endergonic?

Endergonic. You need energy to make energy

172

What is the oxidizing agent of NADH?

ETC

173

The purpose of the redox of the ETC is to move ______ across a membrane...which membrane?

protons, inner membrane

174

What's the enzyme that makes ATP?

ATP synthase

175

It does so because not only is this an enzyme, but it's also a _______ protein. It's specific to transporting _______. When proteins go through it, they turn the rotor, creating ATP.

transport, protons

176

ATP synthase _______ exergonic with endergonic so ATP can be made

couples

177

What is chemiosmosis?

Using a proton gradient to make ATP

178

Making ATP from ADP and inorganic phosphate powered by redox of an electron transport chain is called _________ _________.

oxidative phosphorylation

179

________ _______ means making ATP using the electron transport chain. What's the source of energy?

oxidative phosphorylation, proton gradient

180

Final ATP tabulation (per glucose)
Glycolysis: _ ATP
Citric Acid Cycle: _ ATP
Oxidative phosphorylation: __ or __ ATP
Total: _ ATP

2
2
26 or 28
30 or 32

181

Efficiency of cellular respiration...32%
Is this efficient?

Yeah, pretty efficient. We'll always lose some energy as heat (2nd Law)

182

The ETC is oxidized by _______.

Oxygen

183

What would happen if you no longer had the oxygen to be that terminal electron acceptor?

The ETC will have nobody to give its electrons to. It will back will back up with electrons, and then NADH will back up with electrons, and we'll have nobody to give our electrons to.

184

What if O2 is unavailable?

1) The chain fills up with electrons and stops functioning
2) NADH has no oxidizing agent

185

What's the solution?

Fermentation

186

Fermentation is a type of catabolism without _______.

oxygen

187

Fermentation is not going to completely breakdown sugar...it's a partial breakdown. We're going to do _______, and that's about it.

glycolysis

188

How will we accomplish glycolysis without NAD+? All the NAD+ has been converted into NADH in the absence of O2
The final solution to this problem:
We're going to oxidize NADH using _______.

pyruvate. Using the final product of glycolysis

189

If you oxidize NADH with pyruvate, the pyruvate becomes ______ _______.

Lactic acid, or "lactate"

190

Hence the name, lactic acid _________.

fermentation

191

Do bacteria do fermentation or cellular respiration?

BOTH

192

It is across the ____ ________ that bacteria generate the proton gradient, and at that cell membrane where bacteria make ___.

cell membrane, ATP

193

Single celled life also run aerobic ________ _________, including bacteria and yeast.

cellular respiration

194

Who is the oxidizing agent in fermentation?

NAD+

195

Recall, the function of carbs, lipids, protein is to...? Two things

1) store energy
2) carbon source

196

Intermediates are used for _________ pathways. (Arrows going in and out)

anabolic

197

Cellular respiration is regulated through the enzyme ___.

PFK

198

PFK catalyzes the _____ step of glycolysis

third

199

PFK has ________ sites

allosteric

200

PFK can be turned __ or turned ___, depending on who binds where.

on, off

201

PFK is controlled by _________ inhibition.

feedback

202

PFK is turned off when ___ binds to it.

ATP

203

ADP and AMP can bind to ___ and stimulate it...turn it on.

PFK

204

Citrate also regulates ___.

PFK

205

_____ binds to PFK and turns it off.

Citrate