Chapters 9-11

Requirements of Cells

• Energy

• Organic Building blocks

Phases of Glycogenesis

• Preparation for cleavage: carbon molecule is phosphorylated twice using ATP and split into two glyceraldehyde-3-phosphate molecules

• Oxidatoin and ATP generation: two molecules of glyceraldehyde-3-phosphate are oxidized to form 3-phosphoglycerate, and 2 ATP and two NADH

• Pyruvate formation and ATP generation: two 3-phosphoglycerate are converted to pyruvate and two additional ATP molecules are generated

Aerobic Fermentation

pyruvate is converted to an activated from as acetyl COA

Aerobic Fermentation

pyruvate is oxidized and decarboxylated by pyruvate dehydrogenase (PHD) to form acetyl-COA + CO2 and NAD+ becomes NADH

Acetyl-COA

enters aerobic respiration where NADH is later oxidized back to NAD+

Anaerobic Fermentation

pyruvate is reduced so that NADH can be oxidized into NAD+, that is required for Gly-6 of glycolysis. This produces either: lactate, or ethanol and CO2 at 7% efficiency but well conserved in ATP

Glucogenesis

the process of making new glucose from non-carbohydrate sources to maintain blood sugar levels

• operates in the reverse steps of Glycolysis

Mitochondrial Abundance

vary in number: 0 in red blood cells: hundreds-thousands in energy-demanding cells

Steps of Aerobic Respiration

• Glycolysis

• pyruvate oxidation

• the citric acid cycle

• electron transfer chain

• ATP synthesis

Steps of Electron Transport Chain

• electrons flow from coenzymes, NADH and FADH2

• electrons are passed along and complexes to oxygen to form water

• coupled with accumulation of proton in the mitochondrial cristae

• an electrochemical proton gradient

• this H+ gradient is used to drive ATP synthase

F0 Static Component of ATP Synthase

consists of one alpha and two beta subunits. This alpha subunit forms the proton channel and is immobilized in the membrane. The beta subunits form the peripheral stalk and are attached both the the alpha subunit and F1

The F0 Mobile Component in ATP Synthase

consists of a ring of ten c subunits. Only one c subunit can form an ionic bond with the alpha subunit at a time. For each proton translocated, the ring rotates to the adjacent c subunit and bonds with the alpha subunit

The F1 Static Component of ATP Synthase

consists of the delta subunit plus a catalytic ring formed by a hexagon of alternating alpha and beta subunits. The alpha/beta ring is the site of ATP synthesis and is immobilized by the delta subunit, which connects to the b2 stalk and F0

The F1 Mobile Component of ATP Synthase

consists of the epsilon and gamma subunits, which form the central stalk that is firmly attached to the c10 ring of F0. As proton translocation turns the c10 rung, the gamma subunit rotates insude the alpha/beta catalytic ring of F1

mitochondrial cristae

highly convoluted folds of the inner mitochondrial membrane

Electron Transfer Chain: Complex I

pumps 4 protons from the matrix to the intermembrane space and passes elctrons from NADH to Coenzyme Q

Electron Transfer Chain: Complex II

does not pump protons but does pass some electrons to the quinone pool

Electron Transfer Chain: Complex III

pumps 4 protons form the matrix to the intermembrane space and passes electrons from coenzyme Q to cytochrome C

Electron Transfer Chain: Complex IV

pumps 2 protons from the matrix to the intermembrane space and passes electrons from cytochrome c to oxygen to form water

Electron Transfer Chain: ATP Sytnhase Complex

generates ATP on the matrix side of the membrane due to protons passing through the complex → 1 ATP per 3 protons

Composition of eukaryotic photosynthetic organelle

outer membrane, inner membrane, thylakoids

Chlorophyll

a porphyrin ring structure, long hydrocarbon tail, and a central magnesium ion

Photochemical Reduction

transfer of the energy to another molecule

where does the Calvin Cycle Take Place

in the stroma of chloroplasts

Phases of the Calvin Cycle

fixation, reduction, regeneration