Download III. Cells and Energy

III. Cells and Energy
A. Energy Transfer in Cells
1. Carbohydrates such as glucose provide
energy for the cell. However, they cannot
be used directly, They must be converted
to ATP
2. ATP Adenosine Triphosphate is the
energy molecule of the cell.
Adenosine Triphosphate
3. How ATP works
ATP links Anabolism (building molecules) and
catabolism (breaking down molecules)!!!!!
Catabolism
ATP is formed from ADP and Pi
when energy is released by breaking
the bonds of fuel molecules during
cellular respiration
Anabolism
When ATP is broken down
forming ADP and Pi energy is
released to build molecules
such as proteins
4. How ATP is Produced:
Respiration
IN
Mitochondrion
Out
Glucose
Carbon Dioxide
Oxygen
Water
ADP
ATP
Free Phosphate(Pi)
The ATP can be used directly to power life processes
B. Capturing Light Energy:
Photosynthesis
1. Requirements and products of photosynthesis
IN
Carbon Dioxide
Water
Light Energy
Chloroplast
Out
Glucose
Oxygen
Water
2. Stages of Photosynthesis
A) Light Reaction- traps light energy to make ATP
– Light strikes chlorophyll and electrons are boosted to a high
energy state
– Electrons flow down the electron transport chain and convert
ADP to ATP
B) Water is split
– NADP captures hydrogen and becomes NADPH
– Oxygen is given off as waste
C) The ATP and NADPH are used in the Dark reaction
Light boost the electron to a
NADP forming NADPH
A photon of light
strikes chlorophyll
and a water
molecule is split
As electrons move down
the electron transport
chain, hydrogen ions are
pumped into thylkoid
Hydrogen
ions flow
through
ATPsyntase
forming ATP
from ADP
3. 2nd Stage of Photosynthesis: Dark Reaction- Uses
the ATP from the light reaction to join the carbon dioxide
(from the atmosphere) and hydrogen (from NADPH) to
form glucose in a series of reactions called the Calvin
Cycle
Carbon Dioxide
NADPH
ATP
IN
Glucose
Calvin
Cycle
Out
NADP
ADP + Pi
Carbon dioxide joins with RuBP
to form a six carbon molecule
The six carbon
molecule splits
forming 3 carbon
molecule called 3-PGA
The remaining
molecule are
converted to RuBP
The Calvin
Cycle
One molecule of 3GP exits
Energy from ATP and
hydrogen from NADPH are
added forming G3P
C. Energy Release
1. Anaerobic Respiration- the breakdown of
glucose to produce 2ATP without using oxygen.
a) Glycolysis- breaking glucose in two. This
produces 2 ATP and Lactic acid
1) Lactic acid causes muscle fatigue
2) Lactic Acid produced by bacteria gives food a sour
taste. Vinegar, sour cream, pickles etc
IN
Glucose
2(ADP + Pi)
OUT
Lactic Acid
Bacteria
2 ATP
Anaerobic Respiration
b) Fermentation- breaking down glucose
into Alcohol and Carbon Dioxide to
produce 2 ATP
1) Fermentation produces beer and wine
2) Fermentation causes bread to rise
IN
Out
Glucose
Alcohol
Carbon Dioxide
2ATP
2(ADP + Pi)
Yeast
Aerobic Respiration
2. Aerobic Respiration- The break down of
glucose with oxygen to produce 38 ATP.
Involve 4 Steps:
Step 1: Glycolysis
(Occurs in cytoplasm)
Glucose is broken in half producing Pyruvic Acid and 2 ATP
Step 2: Pyruvic Acid Conversion
(in Mitochondria)
Pyruvic acid is converted to Carbon Dioxide
and Acetyl groups
Carbon Dioxide
Acetyl Groups
Pyruvic Acid
Step 3: Kreb’s Cycle
The Acetyl groups have their hydrogen stripped away
releasing CO2 and 2 ATP
Kreb’s
Hydrogen
NADNADH
Carbon Dioxide
Acetyl groups
2 ATP
Cycle
Step 4: Electron Transport Chain
Hydrogen moves down the electron transport chain
producing 34 ATP. The hydrogen then joins with
oxygen to form water
ADP + Pi
34 ATP