Download Biology Top 101

Biology Benchmark I Review
Chemistry, Cells and Cell
Processes, Bioenergetic Reactions,
and Ecology
Chemistry Review
Organic Compounds
• All living things are made of organic
compounds.
• Organic compounds contain the
elements Carbon and Hydrogen
• 4 important organic compounds are:
Carbohydrates
Lipids
Proteins
Nucleic Acids
Carbohydrates
• Monomer- monosaccharides
(simple sugars like glucose)
• Function- energy source and
structure
•
Tests:
glucose – Benedicts + heat (red)
starch – Iodine (black)
glucose
Examples: Cellulose (plants) structural support
Starch (plants) energy storage
Glycogen (animals) energy storage
•
•
•
•
Lipids
Made of fatty acids and glycerol
Function- energy storage, messengers
Tests: brown paper test (oily spot)
Examples: fats and steroids
(cholesterol, hormones)
Lipid
vs. Water
Proteins
• Monomer- amino acids
• Function- building and repairing cells,
communication, transport, and regulation
• Tests- Biurets (turns purple)
• Examples:
– enzymes: speed up reactions
- hemoglobin: transports O2,
- insulin: regulates sugar
Nucleic Acids
• Monomer- nucleotide
• Function- carry
genetic information
• Ex. DNA and RNA
Nucleotide: a 5 carbon sugar, a
phosphate group, a nitrogen base
Enzymes
• Catalysts in living things (speed up reactions)
• Make reactions happen faster by LOWERING
the activation energy
• Specific to a particular substrate
• Reusable – they don’t change by the reaction
• Affected by temperature and pH and can be
denatured when out of the range.
Acids and Bases
• Living things are
affected by pH.
• Under 7 is an acid.
• Over 7 is a base.
• 7 is neutral.
Buffers
• Buffers help keep pH
stable so enzymes can
function.
• Look at the graph on the
right. What happens
when acid is added to
tap water?
• What happens when acid
is added to liver or
potato?
• Which substances on
the graph appear to be
buffered?
Cells and Cell Processes
Review
Prokaryotes
Cells
• Simple, no membrane
bound organelles
• One circular
chromosome (plasmid)
• Bacteria only
Eukaryotes
• Lots of membrane bound
organelles
• Nucleus containing
linear DNA
• Plants, Animals, Fungus,
Protists
Nucleus
• “Control Center”
• Contains chromosomes/DNA
Mitochondria
Singular: Mitochondrion
• “Powerhouse” of the
cell
• Produces energy in
the form of ATP
• Site of Aerobic
Cellular Respiration
• The cristae (folds
in the organelle)
increase surface
area so more ATP
can be made
Chloroplast
• Site of
photosynthesis
• Plant cells ONLY
• Contains the pigment
chlorophyll
• The thylakoids
(granum) increase
surface area so more
glucose can be made
Vacuole
• Storage of excess
materials
• Plant cells usually
contain one large
vacuole. Animal
cells have lots of
small ones.
Ribosomes
• Proteins are synthesized here
• Found in both prokaryotes and
eukaryotes
Plasma Membrane
aka: Cell Membrane
The cell membrane
regulates what enters
and leaves by size and
charge. To pass easily,
you must be small and
neutral.
• Made of
phospholipids with
embedded proteins
• Surrounds the cell
and regulates what
enters/leaves the
cell
• Helps maintain
homeostasis
Cell Wall
• Plant cells ONLY
• Surrounds cell and provides support and
protection.
• Made of cellulose
Eukaryotes
Plants Vs. Animals
Plant
• Cell wall
• Chloroplast
• Large central vacuole
Animal
• Centrioles (help in cell
division)
• Lots of small vacuoles
Cell Organization
Cell
Tissue
Organ
Organ System
Individual organism
Stem Cells
Stem Cell Type
Embryonic
Adult
Where You Find
Them
The early stages of
embryo
development
In an organism (can
be a juvenile or an
adult)
What They Do
They can replicate infinitely and
they can become any type of cell in
the body.
These cells have already started the
path of differentiation. They
cannot become any type of cell but
they can be used to repair the
tissue type in which they were
found.
Stem Cell Differentiation
• Differentiation is when a cell
becomes specialized to do a
certain job.
• This happens because only
certain genes in the DNA are
turned on.
• Even though all cells in the
body have the same DNA,
the cells are different from
each other because
different DNA is active in a
skin cell vs. a liver cell.
Cell Specialization
• Cells develop to perform different
functions so they look different.
• Examples of specialized cells include:
red blood cells – have hemoglobin to help
transport oxygen
nerve cells – long and thin to transmit impulses
muscle cells – have lots of mitochondria for energy
sperm cells – have flagella to swim
xylem and phloem cells – tubes that help transport
materials for plants
Cell to Cell Communication:
Short Distance
• Cells that touch or
have a very small
distance can use
chemical or
electrical signals.
• This is how motor
neurons activate
muscles.
Cell to Cell Communication:
Long Distance
• Communication across
long distances require
long-lasting chemicals
like hormones.
• Hormones travel to
target cells and tell
the DNA of that cell
to start doing
something different.
The pituitary gland makes growth hormone which goes to many cells
in the body and tells them to divide, making that body part grow.
Diffusion
• Form of passive transport (NO ENERGY
NEEDED) across a membrane
• Molecules move from high concentration
to low concentration
Osmosis
• Diffusion of water (a form of passive
transport)
Notice how
as time
passes, the
water level
is higher on
the right
side. Why
might that
be?
What happens to a cell the
following situations?
• A cell in salt water – It will shrivel
because it is losing water.
• A cell in distilled water – It will swell,
and possibly burst, because it is taking
in water.
• A plant cell in distilled water – It will
swell but it won’t burst because of the
cell wall.
Active Transport
• Particles moving against
the concentration
gradient which
REQUIRES ENERGY
(ATP)
• Against the
concentration gradient
means moving from low
concentration to high
concentration
Cells often have to use active
transport to pump out toxins
Bioenergetic Reactions
Review
Photosynthesis
• Water and Carbon
Dioxide used to produce
Glucose and Oxygen
• H2O + CO2  C6H12O6 + O2
• Occurs in the chloroplast
Think About Photosynthesis….
• In the set up to the
right, a plant was
placed in water and a
light is shining on
the plant. What gas
to you think is
causing the bubbles
you see?
• What else is the
plant making?
Aerobic Respiration
• Used to release energy (ATP)
for cellular use
• C6H12O6+O2H2O+CO2 + 36 ATP
• Occurs in the mitochondria
• Pretty much EVERYTHING alive
(plants, animals, fungus, etc.)
uses this reaction to make their
ATP.
Anaerobic Respiration
aka Fermentation
• Does not require Oxygen
• also used to release energy, but not as
efficient as aerobic respiration (less ATP)
• Products include a couple of ATP, CO2, and
either lactic acid or alcohol
• Two Types: Alcoholic Fermentation and
Lactic Acid Fermentation
Think About Anaerobic
Respiration….
• In the set up to the
right, yeast, sugar,
and water were
combined in the
bottle and a balloon
was placed on top.
What gas is causing
the balloon to
inflate?
• What else is the
yeast making?
ATP
• ATP is energy for
the cell.
• ATP → ADP + P
When a phosphate is
broken off, energy is
released.
• ADP + P → ATP
When a phosphate is
put back on energy is
stored is stored for
later use.
Ecology Review
Ecosystems
• Collection of
abiotic (nonlivng)
and biotic (living)
factors in an area
• Together they
influence growth,
survival, and
productivity of an
organism
Autotroph vs. Heterotroph
• Obtain energy from
the environment
• Photosynthesis or
chemosynthesis
• “Producers”
• Obtain energy from
other living things
• “Consumers”
Symbiotic Relationships
• Relationship
between two
organisms. There
are three types.
• Types:
– Mutualism (+,+)
insects and pollinators
– Parasitism (+,-)
tick on host
– Commensalism (+, o)
barnacles on whale
Predation
• Predator eats prey
• They keep each other’s
population from getting too
high because when the prey
population goes down,
predators go down a bit later
since they have less to eat.
When there are less
predators, the prey numbers
increase. With more prey,
the predators can increase.
This pattern repeats year
after year.
Carrying Capacity
• Maximum number of
individuals that an
ecosystem can
support
• Limiting factors:
–
–
–
–
–
Food availability
Competition
Disease
Predation
Natural Disasters
Carbon Cycle
Look at the
diagram.
What process
pulls CO2 out of
the atmosphere?
What processes
put CO2 back in
to the
atmosphere?
Humans Influence the Carbon
Cycle through Global Warming
• Increase in the average temperature
of the earth
• Caused by the release of too much
CO2 into the atmosphere which
amplifies the greenhouse effect
• Burning of fossil fuels, volcanic
eruptions add CO2.
Nitrogen Cycle
•
Living things need nitrogen to
make all proteins so nitrogen is
necessary for survival.
•
Atmospheric nitrogen gets
converted into a useable form
by bacteria or lightning. Plants
use the nitrogen to grow.
•
Animals get their nitrogen when
they eat plants or other animals.
Colonies of nitrogen
fixing bacteria on plant
roots
Humans Influence the Nitrogen Cycle through
Eutrophication (overfeeding ponds)
• Nitrogen is often
the limiting factor
preventing algae in
ponds from growing.
With extra nitrogen
provided from runoff containing
fertilizer, they grow
explosively and can
cover ponds in a mat,
killing all life below.
Trophic Levels
• Steps in a food
chain/web
• Energy passes from
one organism to
another
• About 10% of the
energy at one level
passes to the next
Human Population
• Growth rate = birth rate - death rate (exponential growth
spiked during the mid 20th Century as a result of better
sanitation, and medical care such as vaccines.
• There are currently 7 billion people on this planet and we
are still growing. Most future growth is predicted to be in
developing nations like India and African countries.
Human Impacts
Negative
Positive
•
•
•
•
Reforestation
Recycling
Sustainable practice
Being good stewards of
the environment
•
•
•
•
•
Acid Rain
Deforestation
Habitat Destruction
Invasive Species
Ozone depletion from
the release of CFCs
• Spraying pesticides
Bioaccumulation
• An increase in
environmental
toxins at higher
tropic levels
• Ex. DDT causing
birds of prey to
lay eggs with
weak shells.
Ecology Issues for North
Carolina
• Acid rain is killing trees in the
mountains
• Habitats are destroyed as we build
houses and widen roads
• Hog farms release lots of nitrogen into
waterways, causing fish kills
• Kudzu is growing over our native plants
• Beaches are eroding on the coast
What NC issue is shown in
each of the pictures below?