Metabolism

METABOLISM

Biochemical processes in a living organism

Metabolism

Require energy

Proteins

Large, complex molecules

Critical roles in structure, function, and regulation of cells

ENZYMES

Proteins that speed up chemical reactions

Enzymes

They are not consumed

Enzymes that help build molecules

Anabolism

Enzymes that help break molecules bonds

Catabolism

Release energy

OXIDATION-REDUCTION REACTIONS

The removal of one of more electrons from molecule

Oxidation

The gain of one or more electrons from molecule

Reduction

PHOTOSYNTHESIS (PS)

Metabolism requires energy

Energy stored in molecules

ATP

PHOTOSYNTHESIS (PS)

Plants are solar powered

Photosynthesis

Chloroplasts

PHOTOSYNTHESIS (PS)

Produce sugar molecule from carbon dioxide and water

Oxygen is the byproduct

PHOTOSYNTHESIS (PS)

Air is composed of

78%

Nitrogen

21%

Oxygen

0.037%

Carbon dioxide

Oceans hold a significant amount

PHOTOSYNTHESIS (PS)

Carbon dioxide fertilization

Pumped into greenhouses

Increase yield 20%

PHOTOSYNTHESIS (PS)

Water

<1% of water absorbed by plants used in PS

Majority is transpired

Water is the source of electrons that drive the PS to create energy and sugar

PHOTOSYNTHESIS (PS)

Light

40% of sunlight is visible

Spectrum used by plants

Violet to blue

Red-orange

PS takes place in chloroplasts

Chlorophyll

PHOTOSYNTHESIS (PS)

Light-Dependent Reactions

Light strikes chlorophyll molecules

Water molecules split apart Photolysis

Release electrons (power)

Hydrogen ions

Oxygen gas

Electrons passed along electron transport system

ATP molecules are produced

Energy molecules

PHOTOSYNTHESIS (PS)

Light-Independent

The Calvin Cycle

H ions from light-dependent PS arrive on NADPH molecule

H fixed to C from carbon dioxide

Form carbon molecules

Carbon molecules converted to glucose (sugar or carbohydrate)

PLANT FOOD

3-carbon molecule

C3 plants

4-carbon molecule

C4 plants

PHOTOSYNTHESIS (PS)

Light-Independent

The Calvin Cycle

C3 plants

Adapted to mild climate

Tolerate cold winters

C4 plants

Tropical or warm weather plants

PHOTOSYNTHESIS (PS)

CAM Photosynthesis

Crassulacean acid metabolism

Succulents

Desert plants

Similar to C4 plants

Most of the activity occurs at night when stomata are open

More efficient use of CO2

Conserve water

RESPIRATION

The release of energy from glucose

Growth and maintenance

Occurs 24 hours a day

RESPIRATION

Glycolysis

First major phase in respiration

Glucose converted to fructose

Addition of two phosphates

Fructose is split into two 3-carbon molecules

RESPIRATION

Glycolysis followed by either

Aerobic respiration

Most common

Anaerobic respiration

RESPIRATION

Aerobic respiration

The citric acid cycle (Krebs cycle)

Breaks down 3-carbon molecules from glycolysis

High-energy electrons are released for use in the plant

RESPIRATION

Aerobic respiration

The electron transport system receives electrons from citric acid cycle

Energy released along the way

RESPIRATION

Oxygen is the final receptor of electrons

Combine with hydrogen

Water

One glucose molecule yields 36 ATP molecules of energy

RESPIRATION

Anaerobic respiration

Lack of oxygen

Wet conditions

Not as efficient as aerobic respiration

Net gain of 2 ATP energy molecules

RESPIRATION

Temperature

Respiration rates increase with temperature

>68F

Double or triple

Always respiring

Refrigerating fruit and vegetables

Lower respiration rate

Reduces microbial activity

RESPIRATION

Water

Required for PS and respiration

Plant cells contain >90% water

Seeds contain <10%

Still respiring

Store in dry, cool area

CARBOHYDRATES

Glucose is a simple sugar

Used to produce carbohydrates

Longer, more complex molecules

Sucrose

Starch

Cellulose

ASSIMILATION

Use of carbohydrates to build cell walls and produce protoplasm

Assimilation

DIGESTION

Conversion carbohydrates into useable food

Digestion

https://www.youtube.com/watch?v=YeD9idmcX0w

https://www.youtube.com/watch?v=wJDlxp17rY4