Cells need energy to move, grow, reproduce, etc.

Metabolism is all the chemical activities that keep an organism alive.

Energy is needed for an organism’s

metabolism.

Green plants are examples of

producers.

Organisms that cannot make their own food are called consumers.

Animals are examples of consumers.

Considered the energy “currency” in cells

Living things can use ATP like a battery; it is present in the cytoplasm of every cell

As food in the cells is gradually broken down, the released energy is used to re-form the ATP so that the cell always maintains a supply of this essential molecule.

Animation of ATP

http://www.biologyinmotion.com/atp/index.html

Scientists estimate that more than 2 x 1026 molecules or >160 kg of ATP is formed in the human body daily!

the ATP is synthesized in the tiny energy factories called mitochondria.

Photosynthesis can be described by the following chemical equation:

6 CO2 + 6 H20 C6H12O6 + 6 O2

Photosynthesis Clip

Plants can convert the glucose sugar they make into other organic compounds such as larger sugars, starches, or lipids & proteins.

This occurs in the mitochondria of all cells, in both consumers and producers.

It is the opposite of photosynthesis

It is an aerobic process. Aerobic means “with oxygen”

C6H12O6 + 6 O2 6CO2 + 6H20 + ENERGY

glucose oxygen carbon dioxide water (ATP)

Respiration Clip

Fermentation occurs when oxygen levels are low.

When might this be?

During strenuous exercise

Anaerobic means “without oxygen”.

Fermentation releases less energy than respiration does, occurs in the cytoplasm, and produces a waste product called lactic acid.

Lactic acid is what makes your muscles “burn” during heavy exercise, and be sore afterward.

To supply oxygen to change lactic acid into a harmless substance.

(In other words, to pay the “oxygen debt”)

Do this yourself and then we will compare

Where it occurs: Cytoplasm

Is Oxygen used? NO

Energy produced: LESS

Waste products: lactic acid and H2O

Where it occurs: Mitochondria

Is oxygen used? YES

Energy produced: MORE

Waste products: CO2 and H2O

I. Photosynthesis

A. What is photosynthesis?

1. The process by which a cell captures the energy in sunlight and uses it to make food

2. Photo means “light” and synthesis means “putting together” – using light to make food

B. A Two-stage process

1. Capturing the sun’s energy

a. Occurs in the leaves and other green parts of the plant- leaf cells contain more

chloroplasts than do cells in other parts of the plant

b. Chloroplasts give plants their green color

c. Pigments- colored chemical compounds that absorb light

Pigments capture light energy and use it to power the second stage of photosynthesis

2. Using energy to make food

a. The cell needs two raw materials for the second stage to occur

i. water

ii. carbon dioxide

b. Carbon dioxide from the air enters the plant through small openings on the underside

of the leaves called stomata

c. The water and carbon dioxide undergo a series of chemical reactions powered by the

energy from in the first stage

i. oxygen

ii. glucose

C. The photosynthesis equation

1. 6CO2 + 6H2O yields C6H12O6 + 6O2

carbon water glucose oxygen

dioxide

3. The glucose is the sugar or food for the plant

D. Photosynthesis and Life

1. Autotroph- an organism that makes its own food

2. Heterotroph- an organism that cannot make its own food

Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured

during photosynthesis

Fermentation is the first step of respiration

2ATP

Glucose ------ Acid/Alcohol + CO2

This is the equation for fermentation

What does it mean?

1. Glucose breaks down

2. Energy is release when this happens, the energy is 2ATP. ATP stands for Adenosine Triphosphate,

this is chemical energy

3. The products of this reaction are Acid/Alcohol and carbon dioxide

4. This reaction takes place in the cytoplasm.

5. Takes place in the absence of oxygen.

Respiration

34ATP

Acid/Alcohol + O2 ---------------- CO2 + H2OThis is the equation for respiration.

What does this mean?

1. Acid/Alcohol from fermentation combines with oxygen.

2. During this process energy is released = 34ATP

3. The products are carbon dioxide and water.

4. This reaction takes place in the mitochondria.

5. Take place in the presence of oxygen.

6. Total energy produced is 36ATP.

7. The reason it is 36ATP is that in order for respiration to happen, fermentation must happen. We know

that 2ATP are released in fermentation so we must add this to the 34ATP. 2ATP 34ATP

Glucose ---- CO2 + Acid/Alcohol ---- Acid/Alcohol + O2 ---- CO2 + H2O Fermentation Respiration

The first part of respiration is….

C6H12O6 +

GLUCOSE

6O2

OXYGEN

6CO2 +

CARBON

DIOXIDE

6H2O + ENERGY

WATER

ATP