Bio Final Chapter 9

Front 1

what is cellular respiration?

Back 1

cellular respiration is the controlled release of energy from organic molecules (such as sugars) in cells to form ATP

- Energy is stored in the molecule ATP, the energy currency of the cell

Front 2

Cellular respiration has to be controlled... how and why?

Back 2

Why: explosive

How: Redox reactions - oxidation and reduction

OIL RIG

oxidation: is the loss of electrons and hydrogens

Reduction: is the gains of electrons and

hydrogens

Front 3

glucose catabolism

Back 3

the high energy electrons and hydrogens are stripped from glucose and picked up by NAD+ and FADH

Front 4

electron transport chain

Back 4

NADH and FADH2 passes electrons and hydrogens in a series of steps instead of one explosive reaction

: uses the energy from the electron transfer to form ATP

Front 5

Stages of cellular respiration

Back 5

1. glycolysis

2. Citric acid cycle

3. Oxidative phosphorylation; electron transport and chemiosmosis

Front 6

Glycolysis

Back 6

:happens outside of the mitochondria

in cytoplasm

: breaks down glucose into pyruvate

: glucose splits in half- NAD+ picks up electrons and hydrogen atoms from carbon molecules becoming NADH, some ATP is produced but not enough

Front 7

Glycolysis energy investment phase

Back 7

- 2 molecules of ATP are consumed

- Glucose is phosphorylated twice forming

fructose- 1, 6-bisphosphate

: glucose= 2 ADP + 2 P (ATP is used)

Front 8

Glycolysis energy payoff phase

Back 8

:sugar is split to form two pyruvate molecules

:2 molecules of NAD+ are reduced to NADH

: 4 molecules of ATP are formed by substrate level phosphorylation (new Gain of 2 ATP)

Glucose = 2 pyruvate + 2 H2O

4 ATP formed - 2 ATP used = 2 ATP

2 NAD+ + 4 e- +4 H+ = 2 NADH + 2 H+

Front 9

Substrate level phosphorylation

Back 9

a. occurs during glycolysis and the Krebs Cycle

b. is a precursor for the phosphorylation of glucose

c. is the source for the majority of the ATP produced in aerobic respiration

d. occurs during the Krebs Cycle.

-fancy way of describing the formation of ATP from ADP and inorganic phosphate (Pi), in a process that doesn't require oxidative phosphorylation (the process through which the majority of ATP are made during aerobic respiration).

-It doesn't require oxygen so it can occur in glycolysis, where four ATP are produced by substrate-level phosphorylation: two and only two 1,3-bisphosphoglycerate are converted to 3-phosphoglycerate by transferring a phosphate group to ADP by the enzyme phosphoglycerate kinase; two phosphoenolpyruvate are converted to pyruvate by the transfer of their phosphate groups to ADP by the enzyme pyruvate kinase.

-Once the pyruvate product of glycolysis is moved to the mitochondrial matrix, the pyruvate is converted to acetate and binds Coenzyme A to form Acetyl CoA to enter the Krebs cycle. While the Krebs cycle is oxidative respiration, one more instance of substrate-level phosphorlyation occurs as Guanosine triphosphate (GTP) is created from GDP by transfer of a phosphate group during the conversion of Succinyl CoA to Succinate. This phosphate is transferred to ADP in another substrate-level phosphorylation event.

Front 10

Citric Acid Cycle

Back 10

to begin the citric acid cycle, pyruvate is converted into acetyl CoA

- occurs in the mitochondria matrix

-within the mitochondria, pyruvate is

decarboxylated yielding acetyl-CoA, NADH and CO2

-the citric acid cycle complete the oxidation of organic molecules generating NADH and FADH2 molecules

Front 11

Steps of the citric acid cycle

Back 11

1. Acetyl CoA stokes the fire

2 and 3. NADH, ATP and CO2 are generated during redox reaction

4 and 5: redox reactions generate FADH2 and NADH

Front 12

Oxidative Phosphorylation

Back 12

Most ATP produced

- involves electron transport and chemiosmosis

- occurs in the inner membrane of the

mitochondria

: following glycolysis and citric acid cycle, NADH and FADH2 account for most of the energy extracted from food

: These two electron carries donate electrons to ELectron Transport Chain, which creates a proton motive force by moving H+ across the inner mitochondrial membrane

: the proton motive force (PMF) is used to make ATP and ATP synthesis

Front 13

Electron transport chain summary:

Back 13

:Electrons are transferred from NADH or FADH2 to the electron transport chain.

:The electron transport chain occurs in the folds of mitochondrion inner membrane.

:The chain’s proteins relay electrons to each other while moving protons across the membrane

:Electrons lose free energy as they go down the chain and are finally passed to O2, forming H2O.

:The electron transport chain generates no ATP. The chain’s function is to pump protons into the inter membrane space, creating a

proton gradient or PMF

Front 14

Main jobs of electron transport

Back 14

1. push the H ions out

2. Chemiosmosis: let the H ions flow back into the mitochondrial matrix and turn the wheel of ATP synthesis

Front 15

Chemiosmosis:

Back 15

the energy coupling machine

- electrons transfer in the electron transport chain causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space

: H+ them moves back across the membrane, passing through channels in ATP synthase

: ATP synthase (an enzyme) uses exergonic flow of H+ to drive phosphorylation of ATP

: this is an example of chemiosmosis, The use of energy in a H+ gradient to drive cellular work

Front 16

Importance of oxygen

Back 16

the oxygen you breath pulls electrons from the transport chain and water is formed as a byproduct

: used to pump - creating an area of high H concentration,

: High H concentration flow back across the membrane and this flow spins the turbine which activates the production of ATP

Front 17

Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen

Back 17

most cellular respiration requires O2 to produce ATP

Front 18

Back 18