CP NOTES

Cell Energy

1) General

A) All cells require energy

B) Cells burn food to get energy- respiration - respiratory enzymes- low temps

C) food- organic molecules like carb, lipids, proteins- glucose is most common food molecule

Note- most food is burned to release energy- Some is used for growth and repair

D) Autotrophs- make food

Heterotrophs eat food

E) Most common way to make food- Photosynthesis

F) carbon fixation- using inorganic materials to make organic molecules- making food

G) Ps and Resp are complementary processes- opposite and working together

a) Ps stores energy / resp releases energy

b) Ps makes food / resp burns food

c) Ps produces oxygen / resp uses oxygen

d) Ps uses carbon dioxide and water / resp produces carbon dioxide and water

Note all materials are recycled- only energy must be supplied constantly

H) ATP- used by resp and Ps to store and transfer energy

2) ATP- energy storage molecule used to store and transfer energy during Ps and Resp

ATP- adenosine triphosphate

ADP - adenosine diphosphate

Energy can be stored in ATP by attaching a third P to ADP

Energy can be released by removing the third P from ATP

ADP + P + Energy -----------> ATP (the energy is stored in the molecule)

ATP--------------> ADP + P + Energy (this energy is now available to be used by the cell)

ADP + P + Energy<---------------> ATP

4) PHOTOSYNTHESIS- process by which the energy from sunlight is captured and used to make food molecules where the energy is stored.

A) General Equation

6 CO2 + 6H20 + Energy-------------> C6H12O6+ 6 O2

B) Pigments

1) Chlorophyll- green pigment that captures the energy from light

2) Helper pigments- yellow( Xanthophyll) yellow-orange (carotene) Others

3) Chlorophyll is destroyed sooner by cold weather- other pigments more easily seen -leaves turn color

C) The Details of Ps

1) Ps occurs in two major stages- The Light Phase and the Synthetic Phase (Calvin Cycle) Both occur in the choloroplast found in some plant cells.

2) Light Phase- 3 basic things occur

a) energy is absorbed by chlorophyll- this excites an electron (gives it extra energy)- this excited electron is passed from molecule to molecule along the electron transport chain. Along the way, the extra energy in this electron is used to:

b) split water- this produces oxygen which is released into the environment and hydrogen which is attached to a molecule called NADP (to form NADPH) NADP is related to the vitamin niacin and is used as a place to temporarily store hydrogen

c) The energy from the excited electron is also used to attach a third P to ADP to form ATP- this stores the energy for later use.

3) Synthetic Phase

a) CO2 from the air is combined with Hydrogen from NADPH and energy from ATP to make PGAL

b) 2 PGAL can combine to form glucose

c) PGAl can be used to make other things- lipids, amino acids etc.

E) Other Things of Interest

1) Calvins Experiments with radioactive tracers

2) Plants require certain minerals to make amino acids etc. nitrates & phosphates mainly. These are in plant "food" Not really food since these are inorganic materials

3) Venus Fly Trap eats insects to get these minerals- they can live in poor soil

4) Some bacteria use chemosynthesis to make food- uses chemical energy- these bacteria are found in hot springs and undersea volcanic vents

5) Chlorophyll absorbs all colors of light except green- green reflects The helper pigments absorb the green.

6) When Ps evolved- it changed the earth forever- oxygen was put into the air and the ozone layer formed

7) Ps- provides food, provides oxygen, allows for the ozone layer to protect against UV radiation