Lecture 6 Cellular Metabolism Flashcards Preview

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Flashcards in Lecture 6 Cellular Metabolism Deck (31):
1

Glucose

high energy molecule that we start with
primary substrate(monomer) for cellular respiration
required by brain and CNS

2

ATP

the energy currency molecule
energy contained in phosphate group

3

Pyruvate

end product of glycolysis
branch point between aerobic and anaerobic metabolism
glucose split into two = pyruvate

4

Lactate

end product of anaerobic metabolism

5

Acetyl CoA

the 2 carbon shuttle
a key intermediate in aerobic metabolism

6

NAD+

oxidized coenzyme (also FAD)
lost its electrons, low energy form

7

NADH

reduced coenzyme (also FADH2)
carrier of 2 high energy electrons

8

O2

the final electron acceptor in aerobic metabolism

9

CO2

end product of aerobic metabolism

10

H20

other end product of aerobic metabolism

11

Oxidation of glucose

glucose + 6 02 --> 6CO2 + 6H20 + energy ->ATP,Heat

12

Cellular respiration

metabolism of substrates to release energy to form ATP

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Hexokinase

adds phosphate group to glucose

14

phosphofructokinase

adds phosphate to fructose making it have 2 phosphates major regulatory enzyme

15

Glycolysis

partial breakdown of glucose to pyruvate. glucose -> 2 pyruvate
occurs in cytosol
multi step pathway

16

Energy investment step in glycolysis

adds 2 high energy phosphates from ATP
input 2 ATP

17

Cleavage step in glycolysis

splits 6C sugar into two 3C molecules

18

Energy capture step in glycolysis

yield 2 NADH and 2 ATP

19

NADH in glycolysis

each carries two high energy electrons
NAD+ + 2H (oxidized) --> NADH + H+ (reduced)

20

Aerobic metabolism

pyruvate goes to transition step and then CAC in the mitochondria
NADH donates electrons to the ETC
Requires oxygen

21

Glycolysis aerobic metabolism net yield and product

yield: 2 ATP and 2 NADH per glucose
Product: 2 Pyruvate

22

Anaerobic metabolism

pyruvate is converted to lactate via the lactic acid pathway in the cytosol
NADH is converted back to NAD+ needed to continue glycolysis
oxygen is being reduced while NADH is being oxidized

23

Glycolysis anaerobic metabolism net yield and product

Yield: 2 ATP per glucose
Product: 2 lactate + 2H+

24

Transition step form glycolysis to the Citric Acid Cycle

yield: 1 NADH
product: 1 CO2
acetyl CoA is a key intermediate which transfers 2C units to the Citric Acid Cycle

25

Citric Acid Cycle

occurs in matrix of mitochondria
First step: 2C unit from acetyl CoA combines w/ oxaloacetate(4C) to form citrate (6C)
Second Step: citrate is oxidized back to oxaloacetate
2 Carbon atoms are fully oxidized to form 2 CO2 molecules

26

Net yield and product of Citric Acid Cycle

yield: 3 NADH + 1 FADH2 + 1 ATP
Product: 2 CO2

27

Electrons in the Citric Acid Cycle

high energy electrons are transferred to NADH and FADH2 and carried to the ETC

28

ETC

electron carrier proteins are located in the INNER membrane of the mitochondria
3 major protein complexes (1,3,4)
NADH and FADH2 donate high enery electrons to the ETC
electrons move downhill through ETC release energy for ATP production
02 is the final electron acceptor

29

cytochromes

iron-containing proteins in the ETC

30

ATP synthesis
flow of H+

Chemiostatic coupling mechanism:
ETC complexes act as H+ pumps
H+ is pumped uphill from the matrix into the intermembrane space containing high [H+]
H+ moves back downhill through the ATP synthase in the inner membrane
ATP synthase phosphorylates ADP to ATP

31

Complete oxidation of glucose yield and product

yield: about 30 ATP per glucose
End product: 6 CO2 + 6 H20