Cell Energy

1
Cell Energy

• Chapter 2 Section 2

2
Why do cells need energy?

• Live
• Grow
• Reproduce

3
From Sun to Cell

• The sun provides energy for almost all living
  things.
• Plants capture light energy from the sun and
  change it into food through photosynthesis.
• Once this food is converted into energy it is
  passed on to the organisms that eat it.

4
Food Web
Producers
Carnivores
Herbivores
5
Photosynthesis

• In the chloroplasts of plant cells there is a
  green pigment called chlorophyll which absorbs
  the energy of light.
• Plants use the energy captured by chlorophyll to
  change carbon dioxide (CO2) and water (H2O) into
  food, the simple sugar glucose (C6H12O6) and
  oxygen (O2).
• When plants make glucose, they are converting the
  suns energy into a form of energy that can be
  stored.

6
Photosynthesis

• 6 CO2 6 H2O light energy C6H12O6 6 O2

Carbon Dioxide
Water
Oxygen
Glucose
7
Getting Energy from Food

• After you eat, your body must break down the food
  into a form that your cells can use.
• This can be done in 2 ways
• Cellular Respiration
• Fermentation

8
Cellular Respiration

• Cellular respiration uses oxygen and is a process
  your body uses to obtain energy from food.
• Cellular respiration occurs in the mitochondria.
• During cellular respiration, food (glucose) is
  broken down into CO2 and H2O, and energy is
  released.

9
Cellular Respiration

• Most of this energy is stored as ATP and is used
  to supply energy to fuel the cells activities.
• Most of the energy released is in the form of
  heat and helps maintain your body temperature.

10
Cellular Respiration

• C6H12O6 6 O2 6 CO2 6 H2O energy (ATP)

Carbon Dioxide
Water
Oxygen
Glucose
11
Photosynthesis and Respiration Whats the
Connection?
Photosynthesis
6 CO2 6 H2O light energy C6H12O6 6 O2
Cellular Respiration
C6H12O6 6 O2 6 CO2 6 H2O energy (ATP)
12
Fermentation

• Have you ever run so far or lifted weights so
  much that your muscles start to burn?
• When your muscle cells cant get the oxygen they
  need to produce ATP by cellular respiration,
  fermentation happens.

13
Fermentation

• Fermentation does not use oxygen and leads to the
  production of a small amount of ATP and products
  from the partial breakdown of glucose.
• There are 2 types of fermentation
• Occurs in muscle cells
• Occurs in certain bacteria and yeast