Download Cell Energy (Photosynthesis and Respiration) Notes

Cell Energy (Photosynthesis and Respiration) Notes
I. Energy – ability to do work; forms of energy: heat, light,
chemical, electrical, mechanical, kinetic, potential
A. Energy for living things comes from - food
Originally the energy in food comes from - sun
B. Uses light energy from the sun to produce food –
autotrophs
Examples: plants + some microorganisms
(bacteria and protists)
C. Cannot use the sun’s energy to make food –
heterotrophs; obtain energy from food they consume
Examples: animals, fungi, most microorganisms
II. Cell Energy – needed for active transport, making
proteins and nucleic acids, chemical signals (fireflies’
light)
A. Cells usable source of energy – ATP
1. ATP stands for adenosine triphosphate
ATP
3 Phosphate groups
adenine
ribose
2. ADP stands for – adenosine diphosphate
ADP
2 phosphate groups
adenine
ribose
B. All energy is stored in the bonds of the compound
Breaking the bond releases energy
C. When cell has energy available it can store this
energy by adding a phosphate group to ADP,
producing ATP
D. Example:
ATP
ADP + P + E from breaking bond
ADP + Energy + P
ATP
http://www.youtube.com/
watch?v=bbtqF9q_pFw&NR
=1
III. Photosynthesis – energy of sunlight is converted to
energy of glucose
A. General Formula:
H2O + CO2 + light
water + carbon dioxide + light
C6H12O6 + O2
glucose + oxygen
B. 2 parts of photosynthesis:
1. light reaction – forms ATP and NADPH – contain
chemical E, but are unstable
2. Calvin cycle (dark reaction) – uses E from ATP
and NADPH to produce glucose
C. Photosynthesis occurs in the organelle –
chloroplast
D. Light absorbing (and reflecting) compounds – pigments
Most common photosynthetic compound –
chlorophyll (a + b)
Absorbs light energy needed for photosynthesis to work
Absorption of Light by
Chlorophyll a and Chlorophyll b
F. Sun’s energy is stored in – glucose
light energy
chemical energy
CO2 + H2O + light
Light Dep. Reactions:
•Trap E of sun in
chemical form
•Produces O2,
ATP, NADPH
Light
high E cmpds.
C6H12O6 + O2
Chloroplast
H2O
Calvin Cycle:
•Uses E from Light
Dep. Reactions and
CO2 to make glucose
CO2
NADP+
ADP+P+
Light
Dependent
Reactions
Calvin
Cycle
ATP
NADPH
Light Dep.
Reactions occur
in thylakoid
stroma—Calvin
Cycle occurs here
O2
released
C6H12O6
produced
IV. Cellular Respiration – process by which E of glucose
is released in the cell to be used for life processes
(movement, breathing, blood circulation, etc…)
A. General Formula:
C6H12O6 + 6O2
6CO2 + 6H2O + 36 ATP
B. Cellular respiration occurs in all cells of all organisms –
plants, animals, bacteria
C. Energy stored by photosynthesis in glucose is
converted into the energy of – ATP
E. Respiration requiring oxygen – aerobic respiration
C6H12O6 + 6O2
6CO2 + 6H2O + 36 ATP
1. organelle occurring in – mitochondria
Human cells contain a
specialized structure – the
mitochondrion – that
generates energy.
E. Respiration NOT requiring oxygen – anaerobic
respiration (an = without)
Also called – fermentation
1. Alcoholic Fermentation:
glucose
ethyl alcohol + CO2 + 2 ATP
a. organisms -- yeast, bacteria
b. industries – baking, brewing, wine-making
2. Lactic acid fermentation:
glucose
lactic acid + 2 ATP
a. lactic acid is produced in the muscles during rapid
exercise when the body cannot supply enough
oxygen to tissues (burning painful sensation)
3. occurs in – cytoplasm
Sore Muscles and
AEROBIC
C6H12O6 + O2
CO2 + H2O + 36 ATP
High E e- carried in NADH
O2
High E ecarried in
NADH and
FADH2
Pyruvic Acid
2 3-C molec.
Glucose
1 6-C molec.
Krebs
cycle
Glycolysis
CO2
released
Cytoplasm
2
Mitochondria
2
32
**E transferred from glucose to ATP
3 stages of aerobic respiration:
1. Glycolysis – cytoplasm, 2 ATP
2. Krebs cycle – mitochondria, 2 ATP
3. Electron Transport Chain – mitochondria, 32 ATP
36 ATP
total
E. T. C.
H2 O
released
ANAEROBIC
Pyruvic Acid
2 3-C molec.
Glucose
1 6-C molec.
Glycolysis
Mitochondria
Cytoplasm
2
Fermentation
Yeast
Bacteria
Alcoholic
muscles
Lactic Acid
ANAEROBIC
alcoholic fermentation = 2 ATP
glucose
2 pyruvic acid
lactic acid fermentation = 2 ATP
cytoplasm
mitochondria
AEROBIC
Krebs cycle
ETC = 36 ATP