Lecture 6 Outline (Ch. 9, 10) I.Citric Acid Cycle II.Electron transport chain & oxidative phosphorylation III.Anaerobic respiration IV.Respiration with other molecules V.Chloroplasts VI.Light VI. Summary

Steps of Respiration Glucose is OXIDIZED/REDUCED to _____. Oxygen is OXIDIZED/REDUCED to _____.

Steps of Respiration Stages of respiration: 3. Citric acid cycle Mitochondrial matrix e- transfer: redox

Cellular Respiration 3. Citric acid cycle 2 Acetyl CoA (2C) join oxaloacetate (4C) few ATP so far e- to carriers (NAD+, FAD) now in mito. matrix 2 citrate (6C) converted several steps, 4C lost (CO 2 ) 2 ATP made Where do the outputs go?

In thinking about cellular respiration: a. What is/are the overall function(s) of glycolysis? b. What is/are the overall function(s) of pyruvate oxidation and the Krebs cycle?

Steps of Respiration Stages of respiration: 4. ETC

Cellular Respiration ETC  e- collection molecules embedded on inner mitochondrial membrane Electron transport chain (ETC) accept e- in turn e- ultimately accepted by O 2 (O 2 reduced to H 2 O)

~100 H+ (stored) 10 H 2 O -outputs: ATP (none yet) Where do outputs go? Electron transport chain (ETC) -inputs:per glucose, 10 NADH 2 FADH 2

Cellular Respiration 4. Chemiosmosis ATP synthase: inner mitochondrial membrane H+ stock-piled in inner membrane space = gradient chemiosmosis – ion gradient to do work

Cellular Respiration ATP synthase: enzyme that makes ATP using H+ gradient 3. Chemiosmosis H+ must enter matrix here Generates 1 ATP per ~3.4 H+

In thinking about cellular respiration: a. At what stage(s) in the overall process is each of the reactants used? b. At what stage(s) in the overall process is each of the products produced? C 6 H 12 O 6 + O 2  CO 2 + H 2 O + Energy

Cellular Respiration Summary of respiration KNOW THIS DIAGRAM – EXCELLENT SUMMARY

Cellular Respiration - anaerobic no O 2 – no oxidative phosphorylation fermentation = extension of glycolysis

Cellular Respiration - anaerobic Types of fermentation - 1. alcohol pyruvate converted to acetaldehyde acetaldehyde accepts e- to regenerate NAD+ ethanol produced brewing & baking

Cellular Respiration - anaerobic pyruvate accepts e- to regenerate NAD+ lactate produced Types of fermentation - 2. Lactic acid muscle fatigue & dairy industry

Cellular Respiration Comparison of aerobic vs. anaerobic respiration: ATP per glucose: AerobicAnaerobic initial e- acceptor: final e- acceptor:

Let’s say it takes 1,000 g of glucose to grow 10 g of yeast anaerobically. How many grams of glucose would it take (estimate approximately) to grow 10 g of yeast aerobically? Hint: If it takes X amount of glucose to grow 10 g of yeast without oxygen, what factor would you have to multiply or divide X by to grow 10 g of the same yeast with oxygen?

Cellular Respiration – other biomolecules Glucose catabolism – one option Proteins: Fats: enter CAC or before Catabolized into a.a. Amino group removed (pee out in urine) If have more glucose than needed, can run “backward” to store energy as glycogen or fats!

Self-Check Step of Respiration InputsOutputsCO 2 /H 2 OATP produced e- carriers loaded Glycolysis1 glucose2 pyruvateNone2 net2 NADH Coenzyme Junction Citric Acid Cycle Electron Transport Chain Oxidative phosphorylation & Chemiosmosis Fermentation

Photosynthesis - overview

Overall purpose: Photosynthesis - overview photosynthesis: light  chemical energy complements respiration - light reaction: solar energy harvest - Calvin cycle: energy to organics

chloroplast recap Outer membrane Inner membrane Thylakoid membrane Intermembrane space Stroma Thylakoid space

Photosynthesis - overview Photosynthesis - 1. light reaction: store energy & split water NADPH & ATP given off Chloroplast model:

H 2 O + CO 2 + energy  C 6 H 12 O 6 + O 2 In photosynthesis, water is OXIDIZED/REDUCED to _______ and carbon dioxide is OXIDIZED/REDUCED to ______.

Redox Reactions Equation for photosynthesis CO 2 + H 2 O + light energy C 6 H 12 O 6 + O 2 photo synthesis

Photosynthesis – light absorption visible light ~380 to 750 nm chloroplast pigments – absorb blue-violet & red/orange - transmit and reflect green

pigments: chlorophyll a accessory pigments -energy-absorbing ring -hydrocarbon tail - carotenoids - photoprotective Photosynthesis – light absorption - chlorophyll b

chlorophyll a – abs blue-violet, red ~ , chlorophyll b & carotenoids – abs broadly blue-violet & more wavelengths used for photosynthesis = more light energy absorbed Photosynthesis – light absorption

If a car is red, which light wavelengths are reflected (NOT absorbed)?

Self-Check