Unit 6a and 6b-ATP and Photosynthesis and Anaerobic and Aerobic Cellular Resp.

ATP

Adenosine Triphosphate

Cellular Energy Currency (cell batteries)

Contains 3 phosphate groups

ADP

Adenosine Diphosphate

Contains two phosphate groups

ATP Cycle

Changes occur over and over in cell

Continuous process where cells convert low energy ADP into high energy ATP by adding a phosphate group, and then break down ATP back into ADP to release energy

Steps for ATP cycle

1. Energy is stored in ATP via cellular Resp.; ATP synthase enzyme forms ATP

2. Energy is released as needed for vital cell functions by breaking the “high energy” phosphate bond; ATP becomes ADP as ATPase enzyme breaks bond

3. Energy from chemical bonds in foods is used to “recharge the battery” ; reform ATP

Photosynthesis

Sunlight converted into P.C.B.E. within glucose

occurs within the chloroplasts of producers/Autotrophs

Chloroplasts

Membrane-bound organelles where photosynthesis occurs

Chlorophyll

Green pigment; absorbs red/blue wavelengths of light

What are the two types of chlorophyll and what they reflect?

Chlorophyll A-Deep green

Chlorophyll B-Yellow Green

Accessory (Antennae) pigments

Help chlorophyll collect a greater amount of sunlight; broadens the absorption spectra

Ex. Carotene →reflects orange

Xanthophyll→reflects yellow

Thylakoids

Membrane Structures that contain photosystems; groups of enzymes that contain light absorbing pigments; site of light dependant reactions

Grana

Stacks of thylakoids; maximize membrane area for light absorption and photosystems;

more membrane surface area=greater light absorption

Stroma

Cytosol like liquid of the chloroplasts; site of light independent reactions

Absorption Spectra Diagram

Absorption by all pigments includes all wavelengths except green; reflected green light leads to green plant color

Photosynthetic Reaction

Occurs in two steps.

Light dependant/independent reactions

Happens at the same time (simultaneously)

Light Dependant Reactions

Require water and sunlight; water split; energy saved

Produce oxygen as waste product

Occurs in the thylakoid membrane/photosystems

Light Independent Reactions

“calvin cycle”

require oxygen

produces glucose

RuBisCO Enzyme

Turns atmospheric carbon (in Carbon dioxide) into a usable/organic form; process is called carbon fixation; all organic molecules originate from this

Overall Photosynthetic Reaction

Water and Carbon dioxide plus light →oxygen and glucose

Alternative pathways to the Calvin Cycle

Plants in hot/dry environments need to keep stomata closed to prevent water loss, but with stomata closed they cannot get carbon dioxide for carbon fixation and release toxic oxygen

Stomata

Opens or close depending on the amount of water and Carbon in the guard cells; loss of water in guard cells causing swelling/turgor pressure resulting in stomata opening

CAM plants

Open stomata at night and close them during the day, water conserved

At night, they fix carbon dioxide into a variety of organic compounds that can be released later during the daytime

Allows water conservation; slow growth but possible in deserts

Ex. Cacti, Jade

C4 plants

Contain special leaf cells that perform rapid uptake of carbon dioxide

Allows for efficient photosynthesis during morning and evening

stomata close during the hottest part of the day

Ex. Corn and crabgrass

Cellular Resp.

The process by which cells break down organic compounds (I.e. glucose) to form ATP; ATP provides immediate energy for metabolic function

Anaerobic Cell. Resp. (fermentation)

Production of ATP without the presence of oxygen, or use of mitochondria

two forms of Anaerobic Cell. Resp.

Lactic Acid Fermentation

Used by most bacteria and some animal muscle cells

Overall formula for Lactic Acid Fermentation

Glucose→2 lactic acid and 2 ATP

Ethyl Alcohol Fermentation

Used by most yeast and some bacteria

overall formula for Ethyl Alcohol Fermentation

Glucose→2 ethyl alcohol+2 co2+2 ATP

Glycolysis

First stage in all forms of respiration

one glucose molecule is broken down into 2 pyruvic acid molecules; energy is released to phosphorylate 2 ATP molecules

occurs outside the mitochondria in the cytoplasm; no mitochondria and oxygen required

Aerobic Cell. Resp.

Requires the presence of oxygen and mitochondria

produces much more ATP from 1 glucose molecule than Anaerobic respiration (38 ATP); 19x More efficient

Stages of Aerobic Cellular Respiration

Stage 1: glycolysis in cytoplasm Reactants:glucose and Product is 2 ATP

Stage 2: Formation of Acetyl CoA in Mitochondrial Matrix

Stage 3: Krebs Cycle in Mitochondrial Matrix

Stage 4:Electron Transport Chain in Cristae/inner membrane

Reactants from Stage 2,3,4 :oxygen

Products from stages 2,3,4 : 36 ATP, carbon dioxide and water

Cristae

the cristae folds of the inner membrane provide ample membrane area for ATP synthase enzymes (an integral protein membrane); here is where ATP is made in bulk

More inner membrane surface area= more ATP production

Overall Aerobic Cellular Respiration Equation

Glucose and Oxygen→ carbon dioxide water and 38 ATP

Relationship between photosynthesis and Aerobic Cell. Resp.

Energy FLOWS through life on Earth while matter RECYCLES between organisms, soil, air, and water