CELLULAR ENERGY

PHOTOSYNTHESIS

The Process that Uses the Sun’s energy to make simple sugars

Two Stages Light dependent reactions Light independent reactions (Calvin Cycle)

LIGHT DEPENDENT REACTIONS

Occur in the Chloroplast Where light energy is trapped by the

pigment chlorophyll in the thylakoid membrane

The light energy excites electrons in chlorophyll which are transferred down an electron transport chain where their energy is harvested.

ELECTRON TRANSPORT CHAIN

A series of proteins that are embedded in a membrane (chloroplast in plants, mitochondria in animals) which pass electrons from higher to lower energy states

By doing so generate ATP from ADP Water is split, oxygen is given off and

the hydrogen (H+) are used

LIGHT INDEPENDENT REACTIONS

Also called the Calvin cycle Is a series or reactions that use CO2 to

form six carbon sugars (such as glucose)

These sugars are then used by a plant to grow or for energy storage Why does a plant need to store energy

PHOTOSYNTHESIS REVIEW

Carbon from CO2 is used with energy from the sun to make sugars for the plant to grow and for storage

CELLULAR RESPIRATION

Cellular respiration is the process by which mitochondria break down food molecules to produce ATP

There are 3 stages Glycolysis Citric Acid Cycle (Krebs Cycle) Electron Transport Chain

GLYCOLYSIS

Is a series of chemical reactions in the CYTOPLASM of a cell that break down glucose (6 carbon sugar) into two 3 carbon molecules

Requires 2 ATP to start the process and makes 4 ATPs, therefore the net gain is 2 ATP

Gives off CO2 in the process Sends off electrons to the electron transport

chain

Simplified, Glycolysis

breaks down glucose (a six-carbon molecule) into two 3-carbon molecules (pyruvic acid) and makes net 2 ATP

CITRIC ACID CYCLE (KREBS CYCLE)

Uses the 3 carbon molecules (2) from glycolysis in a cycle of chemical reactions to produce 2 ATP and 4 CO2

Also passes more electrons to the electron transport chain from more ATP synthesis

THE ELECTRON TRANSPORT CHAIN

Found on the membrane of the mitochondria for cellular respiration

Passes high energy electrons along specialized proteins from higher to lower energy states until the electrons are accepted by Oxygen Why is oxygen important?

Overall produces 32 ATP per glucose molecule

OVERALL ENERGY YIELD

Glycolysis 4 – 2 = 2 ATP

Citric Acid Cycle 2 ATP

Electron Transport Chain 32 ATP

AEROBIC RESPIRATION

Is a process that occurs in the presence of oxygen, such as cellular respiration

However, if oxygen isn’t available cells can also make limited ATP via anaerobic respiration Process that occurs without air

FERMENTATION

A way by which a cell can continue to produce ATP when it is in a anaerobic environment

2 types Lactic Acid Alcoholic

LACTIC ACID FERMENTATION

Occurs during strenuous exercise and oxygen is not available

Glycolysis still works and the net 2 ATP are still formed

The remaining 3 Carbon molecular byproducts (which normally would go into the citric acid cycle) are converted into lactic acid

LACTIC ACID FERMENTATION

Lactic acid is then sent in the blood to the liver to be converted back into the useable products of the citric acid cycle once oxygen is present again

Large build up can become toxic to the body

ALCOHOLIC FERMENTATION

Primarily used by yeast and bacteria cells to produce CO2 and ethyl alcohol

Net product is 2 ATP per glucose molecule, 2 from glycolysis and 2 alcohol molecules from fermentation to alcohol

Ethyl alcohol is the storage molecule until oxygen is present again

ATP PRODUCTION REVIEW Aerobic respiration

36 ATP Lactic Acid Fermentation

2 ATP Alcoholic Fermentation

2 ATP

PHOTOSYNTHESIS CELLULAR RESPIRATION

Food Synthesized Energy from sun stored

as glucose CO2 taken in Oxygen given off Requires light Occurs only in the

presence of chlorophyll

Food broken down Energy of glucose

released CO2 given off Oxygen taken in CO2 given off Does not require light Occurs in ALL living

cells

OPEN BOOK QUIZ

What is the difference between an Autotroph and a Heterotroph

Which ones run photosynthesis

Give an example of each type