Cellular Respiration and Photosynthesis

All organisms use energy to survive Cells in your body use energy to maintain

the organism in which they make up Examples of different forms of energy

Energy

Light Energy

Heat Energy

Sound Energy

Elastic Energy

Electrical Energy

Motion Energy

Chemical Energy

Cells get energy when the chemical bonds in food are broken such as glucose and starch.

The main form of cellular energy is Adenosine Triphosphate or ATP

Cellular Energy

ATP: stores and releases energy

Phosphates determine how much energy exists

ADP: 2 phosphate groups

ADP is your uncharged battery; ATP is your charged battery

ADP to ATP

Energy is released when the 3rd phosphate group is broken off

How Chemical Equations Work

What goes in

What comes out

Equations are balanced

ATP is the molecule we use to get energy. Now, we need a process in order to get a bunch of ATP so we can use it as energy.

Cellular Respiration: How we get ATP

Starts in the cytoplasm with glycolysis Take one molecule of glucose and through a

series of chemical reactions, we get 2 ATP molecules.

Glucose = C6H12O6

Glucose Chemical Reactions 2 ATP

Cellular Respiration: Step 1

Before step 2 takes place, you must ask a question. “Is oxygen present?”

Cellular Respiration: Step 2 (2 possibilities)

Step 2 if oxygen is present goes to a process called Aerobic Respiration

Aerobic literally means ‘living in air’ Aerobic Respiration is divided into 2 parts

Oxygen present? YES

Part 1 is called the Krebs Cycle This takes place in the mitochondria and

produces 2 more ATP

Aerobic Respiration: Part 1

Part 2 of Aerobic Respiration is called the Electron Transport Chain

Take place in the mitochondria as well but produces 34 more ATP

Total ATP produced: 36 Calculate: 2 + 2 + 34 - 2 = 36

Aerobic Respiration: Part 2

Glycolysis

Krebs Cycle

Electron Transport Chain

Amount used up during process

Summary

Chemical Equation for Aerobic Respiration

Reactants Products 36 ATP

If no oxygen is present, then Part 2 of Cellular Respiration goes to a process called Anaerobic Respiration

Produces only 2 ATP from one glucose molecule

Occurs in the cytoplasm Two types of Anaerobic Respiration

Oxygen present? No

Lactic acid builds up in your muscles after you do exercise.

Type 1: Lactic Acid Fermentation

Used by plant cells and some microorganisms such as yeast

Produces ethyl alcohol and carbon dioxide. Other names are ethanol, pure alcohol, drinking alcohol, and grain alcohol

Type 2: Alcoholic Fermentation

Wine through grapes Mead through honey Beer, whiskey, vodka through grain Rum through sugarcane Bread rises due to the formation of carbon

dioxide

Common products made through alcoholic fermentation

Anaerobic Respiration Summary

Glucose

Lactic Acid Fermentation

Lactic Acid

Alcoholic Fermentation

Ethanol and Carbon Dioxide

Aerobic Respiration Anaerobic Respiration

Oxygen must be present Oxygen NOT needed

Takes place in mitochondria Takes place in cytoplasm

Produces 36 ATP Produces 2 ATP

Compare the Two

Cells get their energy from converting glucose into ATP.

Glucose gets its energy from the main source, which is the sun.

Living things are divided into two categories

Energy: the source

Heterotrophs: organisms that must eat other organisms to survive (consumers)

Autotrophs: Organisms that use the energy directly from the sun (producers)

Two types of living things

The process that uses the energy from the sun to change water and carbon dioxide into glucose and oxygen.

The equation for Photosynthesis

Photosynthesis

Inorganic: cannot consume

Organic: CAN consume

Photosynthesis ‘fixes’ carbon so we can eat it though a process called carbon fixation

Fixing Carbon

Light dependent reactions Must have light Chlorophyll, the green pigment in

chloroplasts, absorbs sunlight. This energy is used to convert ADP to ATP Water molecules are split to form oxygen,

hydrogen ions, and electrons

Photosynthesis: Part 1

NADP: a molecule similar to ADP that carries hydrogen ions to the next step which then becomes NADPH

The ADP cousin

CO2 H+

6CO2 + 6H2OO2

NADP

This stage is called the Calvin Cycle also called light independent reaction

Light is NOT needed here

Photosynthesis: Part 2

CO2 + H+ C6H12O6

Both equations are opposites

Cellular Respiration Photosynthesis

Takes place where? All cells Cells with chlorophyll

Occurs when? All of the time In the presence of light

What goes in? (the reactants)

Glucose and oxygen Carbon dioxide and water

What comes out? (the products)

Carbon dioxide and water

Glucose and oxygen

Energy source? Chemical bonds in glucose

Light

Result? Energy is stored as ATP

Energy is stored as glucose

Comparison Chart