Transcript Cells and energy - whsbaumanbiology

CELLS AND ENERGY
Chapter 4
Sections 1, 2, 4, 6
4.1 Chemical Energy and ATP
Connect the role of ATP to energy transfers within a cell
4.1 Chemical Energy and ATP
The chemical energy used for most
cell processes is carried by ATP
A. Molecules in food store chemical
energy in their bonds
B. ATP transfers energy from the
breakdown of food molecules to cell
functions.
1.
Energy is released when a phosphate
group is removed
2. ADP is changed into ATP when a
phosphate group is added
adenosine
triphosphate
phosphate removed
tri=3
adenosine
di=2
diphosphate
4.1 Chemical Energy and ATP
Organisms break down carbonbased molecules to produce ATP
A. Carbohydrates are the molecules
most commonly broken down to
make ATP
1.
Not stored in large amounts
2. Up to 36 ATP from one glucose
molecule
B. Fats store the most energy
1.
80% of the energy in your body
2. About 146 ATP from a triglyceride
C. Proteins are least likely to be broken
down to make ATP
1.
Amino acids not usually needed for
energy
2. About the same amount of energy as a
carbohydrate
4.1 Chemical Energy and ATP
A few types of organisms do not
need sunlight and photosynthesis as
a source of energy
A. Some organisms live in places that
never get sunlight
B. In chemosynthesis, chemical energy
is used to build carbon-based
molecules.
1.
Similar to photosynthesis
2. Uses chemical energy instead of light
energy
4.2 Overview of photosynthesis
• Identify the reactants, products, and basic functions of photosynthesis.
4.2 Overview of Photosynthesis
• Photosynthetic organisms are
producers
A. Producers make their own source of
chemical energy.
B. Plants use photosynthesis and are
producers.
C. Photosynthesis captures energy
from sunlight to make sugars.
1.
Chlorophyll is a molecule that absorbs
light energy.
a. In plants, chlorophyll is found in
organelles called chloroplasts.
4.2 Overview of Photosynthesis
• Photosynthesis occurs in
chloroplasts
A. It takes place in two parts of the
chloroplasts.
1.
Grana (thylakoids)
2. Stroma
grana (thylakoids)
chloroplast
stroma
4.2 Overview of Photosynthesis
B. The light-dependent reactions
capture energy from sunlight.
1.
Takes place in thylakoids
2. Water and sunlight are needed
3. Chlorophyll absorb energy
4. Energy is transferred along thylakoid
membrane then to light-independent
reactions.
5. Oxygen is released
4.2 Overview of Photosynthesis
C. The light-independent reactions
make sugars
1.
Takes place in the stroma
2. Needs carbon dioxide from
atmosphere.
3. Uses energy to build a sugar in a cycle
of chemical reactions
4.2 Overview of Photosynthesis
D. The equation for the overall process
is:
granum (stack of thylakoids)
1
chloroplast
6H2O
6CO2
3
6O2
2
thylakoid
• 6CO2 + 6H2O -> C6H12O6
+ 6O2
energy
stroma (fluid outside the thylakoids)
1 six-carbon sugar
4
C6H12O6
4.4 Overview of Cellular Respiration
Identify the reactants, products, and basic functions of aerobic and
anaerobic cellular respiration.
4.4 Overview of Cellular Respiration
Cellular respiration makes ATP by
breaking down sugars.
A. Cellular respiration is aerobic,
requires oxygen.
B. Aerobic stages take place in the
mitochondria.
mitochondrion
animal cell
4.4 Overview of Cellular Respiration
C. Glycolysis must take place first.
1.
Anaerobic process, no oxygen
2. Takes place in the cytoplasm
3. Splits glucose into three carbon
molecules.
4. Produces 2 ATP molecules
4.4 Overview of Cellular Respiration
• Cellular respiration is like a mirror
image of photosynthesis
A. The Krebs cycle transfers energy to
an electron transport chain.
1.
1
mitochondrion
matrix (area enclosed
by inner membrane)
ATP
and
6CO 2
Takes place in the mitochondrial
matrix.
2. Breaks down three-carbon molecules
from glycolysis.
3. Makes a small amount of ATP
4. Releases carbon dioxide
5. Transfers energy-carrying molecules
energy
2
3
energy from
glycolysis
6O 2
and
inner membrane
ATP
and
6H 2 O
4
4.4 Overview of Cellular Respiration
B. The electron transport chain
produces a large amount of ATP
1.
1
mitochondrion
ATP
matrix (area enclosed
by inner membrane)
and
6CO 2
4. ATP produced
5. Water released as a waste product
2
energy from
glycolysis
6O 2
and
2. Energy transferred to electron
transport chain
3. Oxygen enters process
energy
3
Takes place in the inner membrane
inner membrane
ATP
and
6H 2O
4
4.4 Overview of Cellular Respiration
C. The equation for the overall process
is:
• C6H1206
1.
+ 6O2 -> 6C02 +6H2O
The reactants in photosynthesis are
the same as the products of cellular
respiration.
4.6 Fermentation
Identify the reactants, products, and basic functions of aerobic and
anaerobic cellular respiration.
4.6 Fermentation
• Fermentation allows glycolysis to
continue making ATP when oxygen
is unavailable.
A. Fermentation is an anaerobic
process.
1.
Occurs when oxygen is not available
for cellular respiration
2. Does not produce ATP
4.6 Fermentation
B. NAD+ is recycled to glycolysis
C. Lactic acid fermentation occurs in
muscle cells
1.
Glycolysis splits glucose into two
pyruvate molecules (three-carbon
molecule)
2. Pyruvate and NADH enter
fermentation
3. Energy from NADH converts pyruvate
into lactic acid
4. NADH is changed back into NAD+
4.6 Fermentation
D. Alcoholic fermentation is similar
to lactic acid fermentation
1.
Glycolysis splits glucose and the
products (pyruvate and NADH) enter
fermentation
2. Energy from NADH is used to split
pyruvate into an alcohol and carbon
dioxide
3. NADH is changed back into NAD+
4. NAD+ is recycled to glycolysis
4.6 Fermentation
E.
Fermentation is used in food
production
1. Yogurt (bacteria)
2. Cheese (milk)
3. Bread (yeast)
4. Alcohol (yeast)