Bio Unit 2 (ch. 7-8)

substrate level phosphorylation: process?

way to make ATP through one phosphate, added to ADP to make ATP

Chemiosmosis: process?

main way to make ATP. uses energy from electrochemical gradient

energy intermediates

ATP/ADP, NADH/NAD+, FADH2/FAD

cellular respiration. Where is it happening?

process of cells to obtain energy from organic molecules. It is happening in the cytosol

Glucose

main energy source molecule

anaerobic respiration

does not use oxygen

aerobic respiration

uses oxygen

4 steps of cellular respiration in order:

1. glycolysis

2. Breakdown of pyruvate

3. Citric Acid Cycle/ Krebs cycle

4. oxidative phosphorylation/ ATP synthase

Step 1. Glycolysis

Where does it happen?

What are the phases?

What is the net yield?

Happens in the cytoplasm with or without oxygen

Phase one= energy investment

Phase two= cleavage

phase three= energy liberation

Net yield= 2 ATP, 2 NADH, 2 pyruvate molecules

Glycolysis phase one

energy investment: Glucose 6-Phosphate is turned into fructose-1, 6 bisphosphate. 2 ATP are hydrolyzed (break off of phosphate)

Glycolysis phase two:

Cleavage: 6C molecule from fructose-1, 6 bisphosphate is broken into two 3C molecules called glyceraldehyde-3-phosphate

Glycolysis phase three:

Energy liberation: the two 3C glyceraldehyde-3-phosphate are broken into 2 pyruvate molecules, producing 2 NADH and 4 ATP

Step 2. Breakdown of Pyruvate

Where does it begin?

How does it break down?

What does it join?

What is the Net Yield?

pyruvate begins in the cytosol and is transported to the mitochondrial matrix.

It is broken down by pyruvate dehydrogenase.

The acetyl group (pyruvate) joins CoA and CO2 to make acetyl CoA.

Net Yield= 2 acetyl CoA, 2 NADH, 2 CO2

Step 3. Citric Acid Cycle/ Krebs cycle

What is the process and formula?

What is the cycle?

What is the net yield of one turn?

what is the net yield of two turns?

acetyl is removed from acetyl CoA and attached to oxaloacetate to form citrate

2C acetyl + 4C oxaloacetate = 6C citrate

cycle= 2 turns

one turn net yield= 2 CO2, 1 ATP, 3 NADH, 1 FADH2

two turn net yield= 4 CO2, 2 ATP, 6 NADH, 2 FADH2

Step 4. Oxidative phosphorylation

What is involved?

What is the net yield?

What is the final electron acceptor?

The Electron Transport Chain is involved (ETC)

Net Yield= a LOT of ATP and H2O

Final electron acceptor is O2

ETC

What does it create?

What travels through it?

What does it pump out?

What is the last stage?

Electron transport chain: protein complexes that are embedded in the inner mitochondrial membrane

It creates an H+ electrochemical gradient

electrons stored by NADH travel through the chain

H+ is pumped into the intermembrane space

the last stage is ATP synthase

ATP Synthase

What ion provides the power

phosphorylation of ADP and P to ATP. Last stage of oxidative phosphorylation.

H provides the power for ATP synthase

anaerobic metabolism

metabolism without oxygen

biosphere

regions on earth where organisms live

heterotrophs

organisms that must consume food to live

autotrophs

organisms that produce organic molecules from inorganic molecules to live

photoautotrophs

autotrophs that use light for energy to make organic molecules

Chloroplast

organism that performs photosynthesis

chlorophyll

pigment that makes plants green

mesophyll

the tissue of internal leaf plant where photosynthesis takes place.

contains cells with chloroplasts

thylakoids

flat and fluid filled tubes that enclose the thylakoid lumen in plant cells

granum

structure of stacked thylakoids

stroma

the fluid filled region of the chloroplasts in plant cell

Light Reactions

Where does it take place?

What does it produce?

First stage of photosynthesis

takes place in the thylakoid membrane

Produces ATP, NADPH, and O2 to drive the Calvin cycle

Calvin cycle

Where does it take place?

What does it produce?

what is required per glucose?

Stage 2 of photosynthesis

Takes place in the stroma

Produces carbohydrates from CO2, ATP, and NADPH

6 turns, 18 ATP, 12 NADH and 6 CO2 molecules per 1 glucose molecule

carotenoids

pigment that can absorb light to facilitate photosynthesis in chloroplasts. (main pigment of flowers and fruits)

Photophosphorylation

synthesis of ATP in photosynthesis (form of chemiosmosis)

cyclic photophosphorylation

what does it generate?

pattern of electron flow in the thylakoid membrane is cyclic

only generates ATP in photosynthesis.

Photosystem ll events (3)

1: light excites electron within pigment molecule (P680). The electron moves down ETC and produces an H+ electron chemical gradient

2: 2 Electrons are removed from H2O one at a time, and transferred to pigment P680. (creates O2 and H+)

3: Electrons from PSll reach PSl

Photosystem l events + ATP

1: Electrons are removed from P700. Ferredoxin transfers 2 electrons and 1 H+, to NADP+ to make NADPH. Some H+ is removed from the stroma

2: ATP synthase makes ATP in the thylakoid membrane by using the H+ gradient

light harvesting complex

component of PSll and PSl

dozens of pigment molecules that anchor to proteins

absorb photons of light

photon

discrete particles that make up light

pigment

how does absorption affect electrons?

molecule that can absorb light energy

when pigment absorbs light, electrons are boosted to higher energy level

role of P680

transfer electron to another molecule known as the primary electron acceptor

Calvin cycle stages (3)

1. carbon fixation

2. reduction and carbohydrate production

3. regeneration of ribulose bisphosphate

Carbon fixation process

CO2 is added to RuBP (a 5C sugar)

product is a 6C intermediate that splits into two 3PG (3-phosphoglycerate)

Rubisco

what does it join?

enzyme that catalyzes the first step of calvin cycle. It is the most abundant enzyme on the planet.

Rubisco joins RuBP and CO2

Reduction + Carbohydrate production

ATP converts 3PG to 1,3 BPG

electrons from NADPH reduce 1,3 BPG to G3P (3C atom)

12 G3P are made. 2 used for carb production, 10 used to keep cycle turning

Regeneration of RuBP

6 molecules of ATP are used to convert 10 G3P into 6 RuBP

RuBP serves as CO2 acceptors to keep cycle going

Products of light reactions

ATP, NADPH, O2

stomata

pores in a leaf

absorption spectrum

plots pigment light absorption as a function of the lights wavelength

action spectrum

plots rate of photosynthesis a function of the wavelength of light

noncyclic

linear flow of electrons

how do electrons in the ETC get replaced

oxidization/ split of water