Chapter 10
Energy 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
Phosphate
Adenine
Ribose
ii. ADP is like a re-chargeable battery
Adenosine diphosphate (ADP) + Phosphate
Partially
Charged
Battery
Adenosine triphosphate (ATP)
Fully
Charged
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 transport
2. moving organisms
into the cell
3. Cell growth and
repair
4. 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 phosphate
2. Compare and contrast ATP and ADP. ATP has one
extra phosphate
3. How is energy released from ATP? From the bond
on the third phosphate
4. List three transactions in a cell that require ATP.
Active transport, cell growth, movement
5. What sugar does ADP contain? ribose
6. Where is the energy stored in ATP? From the bond
on the third phosphate
7. 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
• 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:
CO2 + H2O + Light -> O2 + C6H12O6
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
Sugars + O2
CO2 + H2O
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
H2O
Light
ADP
NADP
Light
Dependent
Reactions
Chloroplast
Calvin Cycle
ATP
NADPH
Oxygen
Sugars
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/week
3/06camc4plants.html
Affects on the rate Photosynthesis
1. Intensity of light
2. Amount of water
3. 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