AP Review
Chapters 9-12
Fast Facts
Metabolic pathways that release energy
are called catabolic pathways
- fermentation and cellular respiration
Cellular respiration occurs in the
mitochondria
C6H12O6 + 6O2  6CO2 + 6H2O + Energy
Fast Facts
Redox reactions release energy when electrons
move closer to electronegative atoms
- the relocation of electrons releases the
energy stored in food molecules, and this
energy is used to synthesize ATP
- the loss of e- from one substance is called
oxidation
- the addition of e- to another substance is
called reduction
Fast Facts
Respiration consists of three stages:
- glycolysis, the Krebs cycle, electron
transport chain (ETC)
Glycolysis breaks down 1 glucose into 2
molecules of pyruvate
- occurs in the cytosol
Krebs cycle breaks down pyruvate into
CO2
- occurs in the mitochondrial matrix
Fast Facts
ETC accepts electrons from the
breakdown products of the first 2 stages
- the energy released at each step of
the chain is used to make ATP
(oxidative phosphorylation); through
redox rxns.
oxidative phosphorylation accounts for
90% of generated ATP
Fast Facts
Fast Facts
Glycolysis means “splitting of sugar”
- glucose (6C) 2 pyruvate (3C)
Net energy yield: 2 ATP and 2 NADH
If O2 is present, energy stored in NADH
can be converted to ATP
Fast Facts
Upon entering the
mitochondrion,
each pyruvate is
first converted to
a molecule of
acetyl CoA (2C)
- another NAD+ is
reduced to NADH
Fast Facts
Acetyl CoA will enter
the Krebs cycle for
further oxidation
Krebs cycle
- Acetyl CoA (2C)
enters, 2 CO2 (1C)
leave, 3 NAD+  3
NADH, 1 FAD  1
FADH2, 1 ADP  1
ATP
Fast Facts
Cristae: inner membrane folding of the
mitochondria
- increases surface area for more ETC’s
Inside the inner membrane are enzymes
called ATP synthase.
- makes ATP from ADP and a phosphate
ATP synthase uses energy from the ion
gradient to ATP synthesis.
- proton gradient
Fast Facts
The ETC is an
energy converter
that uses the
exergonic flow of
e- to pump H+
ions across the
membrane
- from the matrix to
the inner
membrane space.
Fast Facts
Fast Facts
Alcohol fermentation: pyruvate  ethanol
- CO2 is released to recycle NAD+
- 2 step process to regenerate NAD+
Lactic acid fermentation: pyruvate 
lactic acid
- lactate is carried away by blood to the
liver; lactate is converted back to
pyruvate by liver cells
Sample Questions
Membranes are important structural
features of cells.
(a) Describe how membrane structure is
related to the transport of materials
across a membrane.
(b) Describe the role of membranes in
the synthesis of ATP in cellular
respiration.
Fast Facts
Chloroplasts are the site of photosynthesis
in plants
All green parts of plants have chloroplasts
- color is from chlorophyll, the green
pigment in the chloroplasts
- CO2 enters/O2 leaves the leaf through pores
called stomata
- water is absorbed through the roots
6CO2+6H2O+lightC6H12O6+6O2
Fast Facts
Photosynthesis is made of two processes,
each containing several steps
1) Light reaction (AKA light harvesting
reaction, light dependent reaction)
2) Calvin cycle (AKA dark reaction,
carbon fixation reaction)
Fast Facts
The light rxn. converts solar energy to
chemical energy; occurs in the
thylokoid membrane
- light absorbed drives a transfer of eand hydrogen to an acceptor, NADP+
- NADP+ is reduced to NADPH
- ATP is generated from ADP through
photophosphorylation
Fast Facts
The Calvin cycle stores the chemical
energy in the form of sugar; occurs in
the stroma
- CO2 is incorporated w/ other
molecules in the chloroplast through
carbon fixation
- fixed carbon is reduced to
carbohydrates
Fast Facts
Fast Facts
In the chloroplasts light
is absorbed mainly by
chlorophyll a.
- blue and red light is
primarily absorbed
- green is the least
absorbent color
Chlorophyll b absorbs
light at slightly
different wavelengths
Fast Facts
Fast Facts
Chloroplasts and mitochondria both
generate ATP through chemiosmosis
- both ETC’s pump protons across the
membrane during the redox rxns.
(transforms redox energy into proton
motive force)
- both use ATP synthase to couple
diffusion to phosphorylation
Fast Facts
Differences between oxidative
phosphorylation and
photophosphorylaton
- in mitochondria, high energy e- are
from food
- in chlorplasts, photosystems capture
light energy to drive e- transfer
Fast Facts
Fast Facts
Calvin Cycle
- uses ATP and
NADPH to
incorporate CO2
into sugar (does
not make glucose
but a 3 carbon
sugar called G3)
Fast Facts
Plants have adapted by developing C4
photosynthesis and CAM
C4 plants preface the Calvin cycle w/ an
alternate mode of carbon fixation
- ex. Sugarcane, corn, grasses
- form a 4-carbon compound as its first
product
Fast Facts
Fast Facts
CAM plants open their stomata at night,
but keep them closed during the day
- found in succulent plants
- at night the CO2 is incorporated into
other organic acids; this mode of carbon
fixation is called crassulacean acid
metabolism (CAM)
Fast Facts
Sample Questions
Describe the biochemical pathways of the
light dependent and carbon fixation
reactions in photosynthesis
Sample Questions
Compare and contrast C4 and CAM
photosynthesis
Fast Facts
Cell division functions in reproduction,
growth, and repair
Cell Division distributes identical sets of
chromosomes to daughter cells
A cell’s genetic material is called its
genome
- prokaryote = single long DNA strand
- eukaryote = number of DNA molecules
Fast Facts
Each duplicated chromosome
has 2 sister chromatids.
- each contains identical
copies of the
chromosome’s DNA
molecule
- they are connected
together at the centromere
Fast Facts
The mitotic phase alternates with
interphase in the cell cycle
The mitotic (M) phase (mitosis and
cytokenesis) is the shortest part of the
cell cycle.
Interphase accounts for about 90% of the
cell cycle.
Fast Facts
- Interphase can be
divided into
subphases G1
(first gap), S
(synthesis), and
G2 (second gap)
Fast Facts
Fast Facts
Fast Facts
Cytokenesis divides the cytoplasm
- in animals, cytokenesis occurs by the
formation of a cleavage furrow
- in plants there is a cleavage cannot
occur because of the cell wall; vesicles
will move to the center of the cell to
form the cell plate.
Fast Facts
The discovery of growth factors has led
us to understand density-dependent
inhibition of cell division
Most animal cells also exhibit anchorage
dependence
- to divide, the cell must be attached to
a substratum (ex. inside of a culture jar
or extracellular matrix of a tissue)
Fast Facts
Sample Questions
Discuss the process of cell division in
animals. Include a description of mitosis
and cytokinesis, and of the other
phases of the cell cycle. Do not include
meiosis.