Chapter 10Energy In a Cell

Cellular Energy Chapter 10

I. ATP• All living things need

energy• In a cell, energy is

released when chemical reactions break chemical bonds

• ATP is adenosine triphosphate- a chemical compound that living organisms use to store and release energy

• 1. It is made when organisims break down glucose and starch.

• ATP has 3 major parts:– A. Adenine– B. Ribose– C. Phosphate

General Structure

b. ATP stores energy when the third phsophate is added

– I. With only two phosphates the molecule is called ADP, or adenosine diphosphate

ADP molecule

Adenine Phosphate

Ribose

ii. ADP is like a re-chargeable battery

Adenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)

PartiallyCharged Battery

FullyCharged Battery

• ii. Because ATP only stores energy for a short period of time the cell has more ADP than ATP

• iii. Cells use the energy from carbohydrates to add phosphates to ADP to create more ATP when needed

c. Energy from ATP Provides energy for metabolic processes

1. active transport2. moving organisms

into the cell3. Cell growth and

repair4. Movement,

digestion etc.

5. ATP moves two potassium and three sodium ions across the sodium-potassium pump in different direction

• ADP + P + Energy ---> ATP

• ATP --> ADP + P + Energy

Copy and complete:1. List the three parts of an ATP molecule. Adenine, ribose

sugar, and phosphate2. Compare and contrast ATP and ADP. ATP has one extra

phosphate3. How is energy released from ATP? From the bond on the

third phosphate4. List three transactions in a cell that require ATP. Active

transport, cell growth, movement5. What sugar does ADP contain? ribose6. Where is the energy stored in ATP? From the bond on the

third phosphate7. What happens to ATP after the energy has been released?

It forms ADP-like an uncharged battery

Photosynthesis

• I. All organisms need energy.– a. The sun is the main source of energy for all

living things

– b. All living things live by releasing energy found in the chemical bonds of compounds such as glucose

– Living things can be:• 1. Autotrophs- organism, like plant, that use

the sun’s energy to make energy containing compounds such as sugar and carbohydrates

• 2. Heterotrophs- organisms, like animals, that get energy from the sun indirectly by consuming food that have energy stored in them

CO2 + H2O + Light -> O2 + C6H12O6

• II. Photosynthesis- process in which autotrophs use the energy in the sun to change water and carbon dioxide (CO2) into simple sugar and oxygen

The equation for photosynthesis is:

There are two main parts of photosynthesis

–a. Light Dependent Reactions» i. This stage requires

light.» ii. Electrons in the

chlorophyll absorb the light energy. -Chlorophyll are structures in the

chloroplasts that reflect green and yellow light and absorbs all others

» iii. Energy from electrons is used to convert ADP to ATP.

Light Energy

CO2 + H2O

Sugars + O2

Sugars + O2

Absorption of Light Energy by Chlorophyll a and Chlorophyll b

» iv. Water molecules are split to form oxygen, hydrogen ions, and electrons

» v. Hydrogen ions attach to carrier molecules to be used in later steps of photosynthesis

» (The carrier molecule NADP becomes NADPH)

Photosynthesis Overview

CO2

ATP NADPH

Oxygen

Light

Sugars

LightDependentReactions

Chloroplast

Calvin Cycle

ATPNADPH

ADP NADP

H2O

b. Light Independent Reaction/The Calvin Cycle

–i. The second part of photosynthesis

–ii.This stage does NOT require light–iii. Enzymes combine carbon dioxide

from the atmosphere with the hydrogen ions (from the light reactions) to form simple sugars

• iv. This stage uses the ATP from the light reactions and stores it in the chemical bonds of glucose

• v. Excess simple sugars are stored as complex carbohydrates---cellulose and starch

• vi. Plants break down the sugars from photosynthesis for growth and development

• http://trc.ucdavis.edu/biosci10v/bis10v/week3/06camc4plants.html

Affects on the rate Photosynthesis

1. Intensity of light2. Amount of water3. Temperature (0-35oC)

Copy and Complete

1. What are the products of photosynthesis? Glucose and oxygen

2. Where does the energy come from to convert ADP to ATP? electrons

3. What three factors influence the rate of photosynthesis? Amount of light , water and temperature