ap bio test 2 review sheet Flashcards
indirect and direct observations are made
observation
hypothesis, a possible, testable explanation for some observed phenomenon.
initial question
An experiment is conducted incorporating experimental subjects, control subjects, and an independent, dependent, and controlled variable.
experimentation
Facts, data, measurement.
results
Explain why you got the results you did. Suggest future tests and how to progress with this information.
discussion/conclusion
made from reading others research
indirect observation
ones that you make yourself.
direct observation
Anything you assert is subject to challenge and may need to be revised. The results of any experiment on any hypothesis must be reproducible. All hypotheses must be falsifiable.
key principles associated with a hypothesis
All living organisms are composed of one or more cells. Cells are the basic unit of structure and function for all living organisms. All cells are produced from other cells.
cell theory
what are the 3 main components of a cell?
A boundary (plasma membrane), a cell body, and a set of genes.
a “fluid” phospholipid bilayer. It is dynamic and made up of different molecules, like phospholipids, proteins, carbohydrates, glycoproteins, and glycolipids. It regulates the movement of molecules in and out of the cell and helps communicate with adjacent cells.
plasma membrane
most common molecules in the plasma membrane
phospholipids
found in organelles, contains organelles, which are specialized structures that aid in cellular growth, metabolism, and reproduction.
cytoplasm
not found in organelles. accounts for ~55% of total cell volume. The composition of cytosol is 75%-90% water.
cytosol
are mostly hydrophobic and associate with lipid tails. They provide rigidity and structure to the plasma membrane.
cholesterol
transverse the plasma membrane, may serve as a channel to transport certain hydrophobic molecules
integral proteins
found on the outside or inside regions of the membrane. may ferry certain molecules across the membrane.
peripheral proteins
bind to a specific molecule (ligand), and some are enzymes.
receptor proteins
Phospholipids may move laterally or flip across their longitudal axis. Proteins may move laterally or through the membrane.
plasma membrane
what are the 5 factors that affect the rate of diffusion?
by size of the concentration gradient, size of the molecules involved (small molecules move faster), temperature of the system (hotter = faster), size of the diffusion membrane (surface area), and the distance molecules must cover to reach the membrane (the closer the molecules are to the membrane, the faster they diffuse).
uses ATP to change the shape of the transporter protein
primary active transport
molecules are brought across the membrane when coupled with a molecule that is diffusing across the membrane due to an established concentration gradient.
secondary active transport
where materials move into the cell in a vesicle.
endocytosis
occurs when membrane receptors bind to specific molecules to bring into the cell.
receptor-mediated endocytosis
where the cell brings in large particles
phagocytosis
where the cell brings in dissolved solutes
pinocytosis
involves secretory vesicles, releasing contents outside of the cell.
exocytosis
extensions of the plasma membrane that are found on the surface of absorptive cells. They increase the cell’s surface area.
microvilli
contain integral protein molecules in the plasma membranes. The proteins help adjacent membranes and help prevent molecules from passing through the intercellular space.
tight junctions
button-like plaques on the plasma membrane. Protein filaments extend from the plagues and lace together the 2 membranes.
demosomes
a communicating junction between adjacent cells. There are different types that are responsible for the movement of different molecules and ions. They are present in heart muscle and smooth muscle.
gap junctions
a network of different protein filaments that extend out into cytosol. It provides a structural framework of a cell and is composed of 3 types of protein filaments.
cytoskeleton
composed of the protein actin. They are involved in muscle contraction, cell division, cell movement, and mechanical support for microvilli.
microfilaments
microfilaments, intermidiate filaments, and microtubules
3 major protein filaments
give strength to proteins, help anchor organelles, and support the cell.
intermediate filaments
large, unbranched, hollow tubes that help determine cell shape. They aid in intracellular transport and the movement of cilia and flagella.
microtubules
DNA is transcripted into RNA, which is translated into polypeptides
central dogma of biology
Some tissues wear away faster than others, and therefor they need to be replenished more than others. These cells will have a faster rate of cellular reproduction than cells that do not need to be replenished as often.
rate of cellular reproduction
why do cells divide?
Cells divide to provide a more favorable surface area to volume relationship. Growth factors and hormones stimulate cell division.
why would cells stop dividing?
Contact inhibition, which tells the cell to stop dividing, and tumors.
can divide to form two new stem cells, “self-revival”, or they can divide to form a stem cell and a progenitor cell.
stem cells
committed cells. They can divide to become any of a restricted number of cells.
progenitor cells
main task of cell reproduction
replicate the dna
what are the 3 tasks accomplished in cell reproduction?
replication and division of organelles and cytoplasm, the equal distribution of DNA to 2 daughter cells, and the establishment of 2 daughter cells.
a pair of chromosomes where each member of the partnership comes from one of the 2 parents of this organism. These chromosomes should not be identical to one another, just as one’s parents should not be identical to one another.
homologous chromosomes
the 2 identical parts of the chromatids formed during DNA replication.
sister chromatids
DNA replicates, chromatin does not condense, and nothing is dividing.
interphase
cellular contents, excluding the chromosomes, are duplicated.
g1 phase
each of the 46 chromosomes is duplicated by the cell.
s phase
the cell “double checks’ the duplicated chromosomes for error, making any needed repairs.
g2 phase
major goal of mitosis
to distribute a copy of each chromatid into each daughter cell.
Duplicated chromosomes are visible. Centrosomes begin moving apart, the nuclear envelope is fragmenting, and the nucleolus will disappear.
prophase
chromosomes (each consisting of two sister chromatids) are at the metaphase plate (center of fully formed spindle).
metaphase
daughter chromosomes (each are consisting of one chromatid) are moving toward the poles of the spindle.
anaphase
daughter cells are forming as nuclear envelopes and nucleoli appear. Chromosomes will become indistinct chromatin.
telophase
prevents uncontrolled cellular divisions. It is regulated by environmental conditions. Contact inhibition occurs when the borders of cells touch, and division stops.
growth control
stimulate cell division, and proteins may bind to these to affect their effectiveness. Some proteins can regulate the expression of genes in RNA, and some can suppress tumors.
growth factors
how do cells know when to divide?
Cells must double their mass and must proceed beyond the “start” of G1 phase.
Duplication and packaging of DNA, duplication of centrosomes and operation of miotic spindle fibers, and cytokines, which depend on the proteins for a contractile ring or cell plate.
3 cycles that trigger the phases of mitosis
water potential calculation
Water potential = pressure potential + solute potential.
looks at how water moves from one compartment to the next. Water potential is affected by relative solute concentrations. If a given solute dissociates in water, this affects how many particles are acting as solutes in a solution, increasing the amount. The water moves from an area of lower concentration of solutes to an area with a higher concentration of solutes. How water moves is dependent upon the pressure exerted by the aqueous solution and solute concentration. The values of water potential inside and outside of the cell help to determine which way the water will move.
water potential
solute potential equation
-iCRT
the i stands for this, which depends upon the number of particles present for a given substances dissolved in water.
ionization constant
C stands for this of the solution
molar concentration
R stands for this
pressure constant
what is the pressure constant?
.0831 liter bars/mol-K
T stands for this
temperature in degrees Kelvin.
