BIO 2050 Exam 3

Cellular Respiration

Process by which living cells obtain energy from organic molecules, typically through glucose.
Goal to make ATP and NADH.

Stages of Cellular Respiration

-Glycolysis - anaerobic
-Breakdown of pyruvate
- Citric acid cycle
-Oxidative phosphorylation

Anaerobic, occurs in cytosol, has 10 steps in 3 phases

Glycolysis

Glycolysis - Phase 1

Energy investment: steps 1-3
2 ATP hydrolyzed to create fructose-1,6 bisphosphate

Glycolysis - Phase 2

Cleavage: steps 4-5
(1)One 6-carbon molecule (fructose-1,6 bisphosphate) broken into (2)two 3-carbon molecules of glyceraldehyde-3-phosphate (G3P)

Glycolysis - Phase 3

Energy liberation: steps 6-10
Two glyceraldehyde-3-phosphate molecules broken down into (2)two pyruvate molecules - (which then) produces 2 NADH and 4 ATP (net yield = 2 ATP)

Glucose metabolism formula/Cellular Resp

C6H12O6 + 6O2 --> 6H2O + 6CO2

Citric Acid Cycle

•In one 'turn' of the cycle a series of Steps releases 3NADH, 2 CO2, 1ATP, and 1FADH2 (PER ACEYTL 2 total)
• Oxaloacetate is regenerated to start the cycle again

Oxidative Phosphorylation via Electron Transport Chain

High energy electrons removed from NADH and FADH2 to create a proton (H+) gradient across the membrane
is aerobic - much more efficent then fermenation
ADP+ Pi = ATP - occurs by ATP synthase
in both mitocondria and chloroplast

Glycolysis

Location - cytoplasm
Input - Glucose, 2 ATP
Product - 2 NADH and 4 ATP (net yield = 2 ATP), 2 Pyruvate

Pyruvate Oxidation

Location - Mitochondrial Matrix.
Input -Pyruvate.
Product Acetyl, 2 NADH

Citric Acid (Krebs) Cycle

Stage 3 of cellular respiration - In Mitochondrial Matrix
Product - 3NADH, 2CO2, 1ATP, 1FADH2 per pyruvate
produces Oxaloacetate as an intermediate

Oxidative Phosphorylation

Location - NADH FADH2, O2
more efficient than fermentation
Product 28-36 ATP

The oxidation of NADH does what for the cell?

It released H+ creating for the electrochemical gradient used to synthesis ATP

Fermentation

breakdown of organic molecules without oxygen
anaerobic

Photosynthesis is what kind of a reaction?

endergonic - needs light energy
Occurs - mainly in leaves, in the mesophyll
light reactions and calvin cycle
Def: Energy within light is captured and used to synthesize carbohydrates

thylakoid

chlorophyll inside

stomata

CO2 enters and O2 exits the leaf through pores

Granum

stack of thylakoids

stroma

the fluid-filled region between thylakoid membrane and inner membrane

Two stages of photosynthesis

light reactions and Calvin cycle

Calvin/Dark/Independent

In stroma - CO2 incorporated into carbohydrates by enzyme Rubisco
Uses NADPH, ATP, CO2

C4 plants

make oxaloacetate - have bundle sheath cells
corn,
alters location of photosynthesis
photosynthesis and Calvin occur in diff locations
photosynthesis takes place in a chloroplast
Calvin cycle occurs in a chloroplast of bundle sheaths

CAM Plants

co2 in at night to keep water in + it makes 4 carbon Malate
During day break down Malate into CO2 to drive Calvin Cycle during the day
plants close their stomata during the day, collect CO2 at night, and store the CO2 in the form of acids until it is needed during the day for photosynthesis

C3 Plants

uses the Calvin cycle, incorporate CO2 into organic material, forming C3.

Calvin Cycle

Phase 1 - Carbon fixation
Phase 2 - Reduction and carbohydrate production
Phase 3 - Regeneration of RuBP