LIVING ORGANISMS & ENERGY

Moretz, Biology

2014

Lecture Outline

• Importance of energy in living organisms

• Photosynthesis• Process of photosynthesis

• Purpose of photosynthesis

• Respiration• Purpose of respiration

• Process of respiration

• Fermentation

Importance of Energy

• Living organisms need energy to do everything.• Move

• Grow

• Reproduce

• Photosynthesis & respiration are needed for living organisms to get energy.

Photosynthesis vs. Respiration

• Photosynthesis- turns energy into sugars

• Respiration- turns sugars into energy

Energy Sugars

Photosynthesis

Respiration

How do plants meet their

energy needs?

Remember, science is a process…..

…..a brief history lesson is in order

The process of understanding

photosynthesis

Until almost 350 years ago, plants were thought to feed on soil

Jan Baptista van Helmont

Planted willow tree in pot

Allowed tree to grow for 5 years

Compared weight of tree and soil to original weight

Tree gained 74kg, soil lost 57g

The process of understanding

photosynthesis

100 yrs later we learned that plants

release oxygen into the atmosphere

Joseph Priestly

Candles “damaged” air

Sprigs of mint “restored” air

The process of understanding

photosynthesis

Finally, ~1800 Jan Ingenhousz

determined:

Air was “restored” only in the presence of

sunlight

Only by a plant’s green leaves, not by it

roots

But, he suggested that the source of the

oxygen was CO2

What is photosynthesis?

photo = light

synthesis = to put together

Process of photosynthesis

• Process by which a cell captures energy and uses it to make food.

• Photosynthesis is a 2 step process:1. Capture energy

2. Turn energy into food

Step 1: Capturing Energy

• Plants capture the light energy from the sun.

• Chlorophyll absorbs the light energy.• Pigment that is good at absorbing a certain wavelength of light.

• Located in the chloroplast.

• Organelle located ONLY in plant cells.

• The light energy captured by the chlorophyll is needed to turn energy into food.

Capturing Energy

Capturing Energy

Capturing Energy

Chlorophyll

Step 2: Turning energy into food

• Plant cells use the captured light energy to produce “food.”

• Water (H2 O) and carbon dioxide (CO2 ) are needed to make the food. • Roots absorb water from the soil.

• Carbon dioxide enters the plant through stomata.

• Light energy changes the water & carbon dioxide into glucose and oxygen (O2).

Stomata

• Small openings on the underside of leaves.

• Gases enter and exit through these openings.

Stomata

• Small openings on the underside of leaves.

• Gases enter and exit through these openings.

Glucose

Glucose = C6H12O6

“Food” produced

during

photosynthesis.

Simple

carbohydrate

(sugar)

Process of photosynthesis

•6 CO2 + 6H2 O C6H12O6 + 6O2

•6 carbon dioxide molecules and 6 water molecules produces 1 glucose molecule and 6 oxygen molecules.

light

Photosynthetic Organisms

Carried out by a variety of organisms,

ranging from simple bacteria, to algae

and complex plants.

Any organism that is able to

photosynthesize is known as a

“producer” or “autotroph.”

Importance of

Photosynthesis

Releases oxygen into the atmosphere.

Dead plant matter is a source of fossil

fuels.

Most living things obtain energy either directly or indirectly from the sun’s energy captured during photosynthesis.

Importance of Photosynthesis

Without photosynthesis, living organisms would not get energy!!!

Energy enters the ecosystem through photosynthesis.

Plants use the sun’s energy to make glucose.

All other organisms consume glucose from the producers as a source of energy.

Flow of Energy

Flow of Energy

CELLULAR RESPIRATIONHARVESTING

CHEMICAL ENERGY

2009-2010

ATP

CO2 + H2O + heatfuel

(carbohydrates)

O2

“Burn fuels” to make energy• Combustion - making heat energy by burning fuels

in one step

ATP

ATP + CO2 + H2O (+ heat)

• Aerobic respiration - making ATP energy (& some

heat) by burning fuels in many small steps

food

(carbohydrates)

O2

Energy needs of life• Animals are energy consumers

•What do we need energy for?• synthesis (building for growth)

• reproduction

• active transport

• movement

• temperature control (making heat)

Where do we get energy?•Energy is stored in organic molecules

•carbohydrates, fats, proteins

•Animals eat these organic molecules food• digest food to get

• fuels for energy (ATP)

• raw materials for building more molecules

• carbohydrates, fats, proteins, nucleic acids

ATP

ATP

What is energy in biology?

Adenosine TriPhosphate

Harvesting energy stored in food• Cellular respiration

• breaking down food to produce ATP

• in mitochondria

• using oxygen

• “aerobic” respiration

• usually digesting glucose

• but could be other sugars, fats, or proteins

C6H12O6 6O2ATP 6CO2 6H2O+ + +

glucose + oxygen energy + carbon + waterdioxide

O2

food ATP

What do we need to make energy?•The “Furnace” for making energy

• mitochondria

•Fuel• food: carbohydrates, fats, proteins

•Helpers• oxygen

• enzymes

•Product• ATP

•Waste products• carbon dioxide

• water

O2

food

ATP

Make ATP!Make ATP!All I do all day…And no oneeven notices!

enzymes

CO2H2O

Mitochondria are everywhere!!animal cells plant cells

Can’t store ATP too unstable

only used in cell

that produces it

only short term

energy storage carbohydrates & fats

are long term

energy storage

Using ATP to do work?

A working muscle recycles over

10 million ATPs per second

ATP

ADP

workAdenosine DiPhosphate

Adenosine TriPhosphate

make energyA Body’s Energy Budget

eat

food

synthesis

(building)

• energy needed

even at rest

• activity

• temperature

control

{• growth

• reproduction

• repair{storage

• glycogen

(animal starch)

• fat{

ATP

1

2

3

What if oxygen is missing?• No oxygen available = can’t complete aerobic respiration

• Anaerobic respiration• also known as fermentation

• alcohol fermentation

• lactic acid fermentation

• no oxygen or no mitochondria (bacteria)

• can only make very little ATP

• large animals cannot survive

O2

yeast

bacteria

Anaerobic respiration

• Alcoholic fermentation

Anaerobic respiration

• Lactic acid fermentation

Anaerobic Respiration• Fermentation

• alcohol fermentation

• yeast

• glucose ATP + CO2+ alcohol

• make beer, wine, bread

• lactic acid fermentation

• bacteria, animals

• glucose ATP + lactic acid

• bacteria make yogurt

• animals feel muscle fatigue

O2

2009-2010

Got the energy…

Ask Questions!!

Respiration is a 2 step process:

1. Glucose is broken into smaller molecules.• Occurs in the cytoplasm.

• Oxygen is not needed.

• A small amount of energy (ATP) is released.

Respiration is a 2 step process:

2. Small molecules are broken into even smaller molecules.• Occurs in the mitochondria.

• Oxygen is required.

• A lot of energy (ATP) is released.

Respiration is a 2 step process:

Respiration is a 2 step process:

Glucose

Small

molecules

Energy

In the cytoplasm

Respiration is a 2 step process:

Oxygen

Smaller

molecules

Water

Carbon

dioxide

LOTS of

Energy

Process of respiration

C6H12O6 + 6O2 6CO2 + 6H2 O + ATP

•One molecule of glucose and six molecules of oxygens make six molecules of carbon dioxide, six water molecules, and ENERGY.

ATP = Energy Universal energy storage molecule.

All organisms break down ATP to get

energy.

Energy is

released when

the chemical

bonds in ATP

are broken.

Photosynthesis & respiration summary

• Glucose is made during photosynthesis.

• Glucose is broken down and energy is released during respiration.

• All organisms use energy released to do everything.

Energy Sugars

Photosynthesis

Respiration