BIOLOGY MIDTERM STUDY GUIDE
1. PHOTOSYNTHESIS – plants and other autotrophs use energy from the sun (light energy) to make glucose (chemical
energy). This process happens in the chloroplasts. The reactants are carbon dioxide, water, and sunlight. The products
are glucose (a carbohydrate or sugar) and oxygen, which we need to breathe. You must know the balanced equation!
2. CELLULAR RESPIRATION happens in the mitochondria. The mitochondria is the power house of the cell – it
provides the cell with energy (ATP). RESPIRATION IS THE OPPOSITE OF PHOTOSYNTHESIS. THE PRODUCTS OF
PHOTOSYNTHESIS ARE THE REACTANTS OF RESPIRATION & THE REACTANTS OF PHOTOSYNTHESIS ARE THE PRODUCTS
OF RESPIRATION. CELLULAR RESPIRATION breaks down glucose and forms 36 ATP. ALL organisms use cellular
respiration but only autotrophs can do photosynthesis.
3. Study your notes on functions of each specific organelle. In addition to these, remember the following:
A. All cells have cytoplasm, DNA, a cell membrane, and ribosomes (used to proteins)
B. Prokaryotic cells (example: bacteria) are much smaller and simpler than eukaryotic cells. They are not as
specialized as eukaryotic cells. They do not have a nucleus or membrane bound organelles (such as
mitochondria, golgi, etc.). They do have a cell wall (like plants). They are unicellular (each organism is a single
cell.
C. Eukaryotic cells (example: plants, animals, fungi) are larger and more complex than prokaryotic cells. Most
organisms that have eukaryotic cells are multicellular (many, usually specialized cells). Eukaryotic cells have a
nucleus that houses its DNA, and other membrane bound organelles.
D. Plant cells are eukaryotic cells. Plant cells differ from animal cells because they have a chloroplast (for
photosynthesis) and a cell wall. Plants are autotrophs or producers.
E. Animal cells don’t have chloroplasts or a cell wall but they do have centrioles which they use for cell division.
MACROMOLECULES
STUDY YOUR GRAPHIC ORGANIZER!!!!
ENZYMES: An enzyme is a protein. An enzyme is a catalyst that speeds up chemical reactions. All chemical reactions
need energy to get them started which is called the activation energy. ENZYMES LOWER THE ACTIVATION ENERGY FOR
REACTIONS so they happen faster. Enzymes don’t make reactions happen that wouldn’t happen anyway. Each enzyme
can only bind to a single substrate (a reactant of the chemical reaction)…enzymes are very specific. The spot on the
enzyme where it binds to the protein is called the active site. This is called a lock and key model. The enzyme and
substrate form an enzyme-substrate complex. When the reaction is complete, the products are released, and the
enzyme will go catalyze another reaction. The enzyme is unchanged and recycled.
Enzymes work best at specific temperatures and pH’s. If either of these is too extreme, the enzyme will change
shape and be unable to fit with the substrate. This is called denaturing and makes the enzyme unusable.
CELLULAR TRANSPORT – Study your vocabulary sheets & notes!
SOLUTIONS
Hypotonic
Less solute outside
the cell than in; water
moves into the cell
(salt sucks the water
in). Animal cells
Isotonic
Equal amounts of
solute inside and
outside the cell.
There is
equilibrium.
Hypertonic
More solute outside the cell than in;
salt sucks the water outside); plant
cells experience plasmolysis where
their cell membrane pulls away from
their cell wall; animal cells shrivel or
shrink
Does it require energy?
PASSIVE TRANSPORT
No
Moves from high to
low concentration or
low to high?
High to low
ACTIVE TRANSPORT
Yes! ATP
Low to high
Examples
Diffusion
Osmosis (water)
Facilitated diffusion
Sodium potassium pump
pinocytosis – cell drinking
phagocytosis – cell eating
exocytosis – exit – sending things
out of the cell
endocytosis – bringing things out
of the cell