energy in a cell terms chemosynthetic organisms that obtain cellular energy by breaking down...

Energy in a Cell

Terms

ChemosyntheticOrganisms that obtain cellular energy by breaking down inorganic chemicals

Autotroph creates their own food through photosynthesis or chemosynthesis. These organisms are producers.Heterotroph

depends upon other organisms for nutrition. These organisms are consumers. Some organisms, such as the Euglena, will be photosynthetic in the presence of light and heterotrophic without light.

Energy Carriers ATP

temporary energy storage molecule in all cells

NADHH+ and e- carrier moleculeNAD + + H+ + e- NADH

FADH2

H+ and e- carrier moleculeFAD + 2H+ + e- FADH2

Think of NADH and FADH2 as taxi cabs!

NADH and FADH2

All Cells Need Energy

Cells need energy to do a variety of work:Making new moleculesBuilding membranes and organelles

Moving molecules in and out of the cell

Movement

Where Does A Cell Get Energy?

Food is broken down to a form the cell can use.

Extra energy is stored in an ATP molecule, a nucleotide.

What Is ATP?

ATP – adenosine triphosphate is a molecule made up of an adenine, ribose, and 3 phosphate groups.

Adenine

Ribose

A Simple Review

What basic unit of what organic compound is pictured to the right?

Adenine

Ribose

P

How Does ATP Work?

Energy is stored in the bond between the second and third phosphate group.

When the bond is broken, energy is released and ADP is formed.

Adenine

Ribose

ATP – Energy Currency

• Within a cell, formation of ATP from ADP and phosphate occurs over and over, storing energy each time.

• As the cell uses energy, ATP breaks down repeatedly to release energy and form ADP and phosphate.

Making Energy

Cells make energy in two ways:Photosynthesis – takes place in the chloroplasts.

Respiration – takes place in the mitochondria.

Photosynthesis

Autotrophs make their own food by trapping light energy and converting it to chemical energy (carbohydrates).

Photosynthesis

Using light from the sun, plants combine water and carbon dioxide to make sugar . General Equation:6CO2 + 12H2O C6H12O6 + 6O2 + 6

H2O

Reactants Products

light

Chemosynthesis Some autotrophs can convert

inorganic substances to energy. Most are adapted to live in

conditions where there is no oxygen. Marshes Lake sediments Digestive tracts of mammals Deep in the ocean

Cellular Respiration The process of breaking down

food molecules to release energy. Aerobic respiration occurs in the

mitochondria. Two types:

Aerobic – requires oxygen.Anaerobic – requires an absence of oxygen.

Cellular Respiration – Chemical Equation

C6H12O6 + 6 O2 _ CO2 + _ H2O + 36-38 ATPenzymes

Cellular Respiration

Cellular Respiration Steps Glycolysis Citric Acid Cycle Electron Transport Chain

1. Glycolysis Glucose is split to form pyruvate. Takes place in the cytoplasm of

the cell. ATP and NADH are byproducts.

Glycolysis Chemical Equation

Glucose + 2 NAD+ + 2 ADP + 2 Pi 2 pyruvate + 2 NADH + 2 ATP + 2 H2O

Enzymes

GlycolysisC6H12O6

C3H3O4

+

NAD+

NADH

2 ATP

ReviewWhat are the inputs for Glycolysis?

Glucose2 ATP

C6H12O6 (6 carbon molecule)2 NAD+ (coenzyme)

2 ADP+P

What are the outputs for Glycolysis?2 pyruvic acid (3 carbon molecules)

2 NADH2 ATP (makes 4 but 2 are needed in the

process)

Anaerobic Respiration Two types of anaerobic respiration:

Fermentation Occurs when bacteria

break down plants (vegetables and fruit) and release alcohol or vinegar.

Lactic Acid Fermentation Occurs in muscles – a buildup of

lactic acid causes soreness.

Aerobic Respiration2. Citric Acid Cycle A.K.A. Kreb’s

Cycle Pyruvate is used to build citric acid (a

carbon compound), which is broken down to release ATP. (# Net 2 ATP)

Takes place in the cristae (the folded membrane in the mitochondrion)

CO2 is released, and NADH & FADH2 carry electrons and hydrogen ions to the electron transport chain.

Each glucose molecule takes two trips around the cycle!

Inputs

Pyruvate

NAD+

FAD

ADP + Pi

Outputs

4 NADH

1 FADH2

1 ATP

3 CO2

Each glucose

molecule takes 2 turns

through the cycle!

Outputs

8 NADH

2 FADH2

2 ATP

6 CO2

3. Electron Transport Chain

Electron Transport Chain Electrons are reduced, and that energy

forms large amounts of ATP. (#32-34 ATP) Takes place in the inner membrane

of the mitochondrion The used ions are combined with

oxygen to form H2O.

Electron Transport System

36-38 ATP

NADH

NAD+

FADH2 FAD

H2O

O2

ReviewWhat are the inputs for the Krebs cycle?

1 Pyruvate (3 carbon molecule)

4 NAD+

1 FAD

1 ADP + Pi

What are the outputs for the Krebs cycle?

(Per 1 pyruvate – 1 glucose yields 2X)4 NADH

1 FADH2

1 ATP

3 CO2

ReviewWhat are the inputs for the ETS per one molecule of

glucose?

10 NADH: 8 from Krebs, 2 from glycolysis

2 FADH2 : from Krebs cycle

O2

What are the outputs for the ETS?

32-24 ATP molecules

H2O

Total ATP Production

36 -38 ATP molecules

C6H12O6 + 6 O2 6 CO2 + 6 H2O + 36-38 ATPenzymes

MITOCHONDRION

CO2

H2O

O2 ATP

NADHFADH2

HeatElectron

TransportSystem

ATP

NAD+

FAD

Pyruvate

GlucoseATP

Sunlight

Photo-System

I

Photo-system

II

NADP+

ADPNADPHATP

CalvinCO2

H2O

O2

ATP

ATP

NAD+

FAD

NADHFADH2

ElectronTransportSystem

Cycle

CitricAcid

Heat

CHLOROPLAST MITOCHONDRIONATP

Glycolysis

Glucose Pyruvate

Cycle

Cycle

CitricAcid

Sunlight

Photo-System

I

Photo-system

II

NADP+

ADPNADPHATP

CycleCalvin CO2

H2O

O2

ATP

ATP

NAD+

FADNADHFADH2

ElectronTransportSystem

Heat

CHLOROPLAST MITOCHONDRION

Glucose

ATP

Pyruvate

Glycolysis

Cellular Respiration

C6H12O6 + O2 CO2 + H2O + 36-38 ATP6 66

Oxidation - Reduction

Oxidation is the loss of elecrons from an atom or molecule. It is also the loss (removal) of hydrogen atoms from a molecule. A loss of energy is associated with the loss of electrons or hydrogen atoms.

Reduction is the gain of electrons or the gain of hydrogen atoms. This process stores energy.

Oxidation - Reduction

Oxidation and reduction occur together. When a atom or molecule is oxidized, another must be reduced.

Example: Na + Cl ®  Na+Cl-  - The Na is oxidized; the Cl is reduced.