AP bio Unit 2 Flashcards
Domains with prokaryotic cells
Bacteria and Archaea
location of DNA in prokaryotic cells
nucleoid floating in cytoplasm
location of DNA in eukaryotic cells
nucleus
endosymbiont
a cell that lives within a host cell
cell wall function
protection, structural support
plasma membrane structure
phospholipid bilayer with embedded proteins
plasma membrane function
selective permeability- maintains intracellular environment
bacterial chromosome
The DNA of a prokaryotic cell which is located in the nucleoid
Nucleoid
A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.
Cytoplasm
the region inside the cell except for the nucleus
Why cells are small
A cell’s surface area to volume ratio limits the size of the cells because they need nutrients which come from the outside
surface area to volume in cells
the surface area to the volume ratio gets smaller as the cell gets larger
Microvilli
projections that increase the cell’s surface area
Prokaryotic versus eukaryotic cells
Eukaryotic cells have nucleus while prokaryotic cells don’t have nucleus.
nuclear envelope
double membrane that surrounds the nucleus
nuclear lamina
A netlike array of protein filaments lining the inner surface of the nuclear envelope.
function of the nuclear lamina
It helps maintain the shape of the nucleus.
Chromatin
Clusters of DNA, RNA, and proteins in the nucleus of a cell
chromatin forming chromosomes
form loops and coils to condense
Nucleolus
Found inside the nucleus and produces ribosomes and RNA
Ribosomes
Makes proteins
free ribosome location
cytosol
cytosol
Fluid portion of cytoplasm
bound ribosome location
attached to the ER
Free ribosome product
enzymes that catalyze sugar breakdown
bound ribosome product
proteins that go into membranes
Rough ER structure
Continuous with the nuclear envelope, separates the cisternal space inside from the cytosol on the outside.
function of Rough ER
Produces proteins from ribosomes, assists in protein folding, transports vesicles, and synthesizes membrane proteins and phospholipids.
Rough ER in protein production
It produces proteins from ribosomes and helps in their folding within the ER lumen.
Smooth ER structure
Membranous system of sacs and tubules; free of ribosomes
Smooth ER function
ER synthesizes lipids, metabolizes carbs, detoxifies poisons, stores calcium ions
Golgi apparatus structure
a stack of flattened membranes and associated vesicles close to the nucleus
Golgi apparatus function
modifies and packages proteins
Lysosomes
An organelle containing digestive enzymes
food vacuole
formed when a unicellular organism engulfs food particles or a white blood cell engulfs invaders. This is called phagocytosis
contractile vacuole
pumps excess water out of the cells
central vacuole
located in mature plant cells, contains cell sap
Cell Sap (Central Vacuole)
mix of inorganic ions like potassium and chloride
Flow of materials in cell export
ER to Golgi to Vesicle to Cell membrane
digestive enzymes in lysosomes
have special shapes to prevent the membrane from being digested.
Phagocytosis
process in which extensions of cytoplasm surround and engulf large particles and take them into the cell
Choloroplasts
where photosynthesis occurs. This is the conversion of sunlight into chemical energy.
Cytoskeleton
a network of fibers that organizes structures and activities in the cell.
two roles of the cytoskeleton
support and motility
structure of cell wall
The cell wall consists of the primary cell walls, the middle lamella, and secondary cell walls
endosymbiont theory
explains that eukaryotic cells may have evolved from prokaryotic cells
evidence for endosymbiont theory
double membrane, ribosomes, circular DNA, capable of functioning on their own
selective permeability
A property of a plasma membrane that allows some substances to cross more easily than others.
amphipathic
having both a hydrophilic region and a hydrophobic region
fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.
temperature’s effect on membrane fluidity
increase temp= increase fluidity
unsaturated hydrocarbon chains’ effect on fluidity
more = longer to solidify
Cholesterol and fluidity
Acts as a fluidity buffer. Makes it less fluid at higher temps by restraining movement. However, makes in more fluid at lower temperatures becaus it creates space.
integral proteins
penetrate the hydrophobic interior of the lipid bilayer
peripheral proteins
bound to the surface of the membrane
transport proteins
allow passage of hydrophilic substances across the membrane
enzymatic activity
A protein built into the membrane with active site exposed to carry out important steps
signal transduction protein
A membrane protein with a shape that fits a chemical messenger like a hormone used to send messages
Cell-cell recognition proteins
Identification between cells.
intercellular joining proteins
membrane proteins of adjacent cells may hook together in various kinds of junctions
protein attachment to cytoskeleton and ECM
microfilaments non covalently bound to membrane proteins for stabilization
Membrane carbohydrates functions
cell recognition, anchor cells together
channel proteins
provide corridors that allow a specific molecule or ion to cross the membrane
carrier proteins
bind to molecules and change shape to shuttle them across the membrane
Aquaporins
water channel proteins
CO2 diffusion
easily pass through without help
Glucose diffusion
hard to get through without a carrier protein because it’s polar
hydrogen ion transport through membrane
can’t pass through by itself
Oxygen diffusion across bilayer
direction of concentration gradient
H2O diffusion across cell membrane
hard to get through by itself, usually goes through aquaporins
golgi apparatus
packages and processes
Vesicles
membrane sacs for transport in cell
Mitochondria
produces ATP via cellular respiration with requirement of oxygen
flagella/cilia
motion
Hypertonic
A solution with a higher concentration of solute than the cell
Hypotonic
A solution with a lower concentration of solute than the cell
Isotonic
Having the same solute concentration as the cell
turgid
The healthy state of plant cells where the cell is very firm and the inside of the cell is pushing against the outside. The outside of the cell is hypotonic.
Flaccid
Plant cell in an isotonic solution, the plant will wilt because there’s not enough pressure
Plasmolysis
Plant cell in a hypertonic environment, the cell will lose water and the plasma membrane pulls away from the cell wall
Facilitated diffusion
passive transport aided by proteins
Active transport
Pumping a solute against its concentration gradient with the requirement of energy from the cell. This energy is usually ATP
sodium-potassium pump
a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell
membrane potential
The voltage across a cell’s plasma membrane.
positive membrane potential
Extracellular side
Endocytosis
process by which a cell takes material into the cell by infolding of the cell membrane
Phagocytosis
A type of endocytosis in which a cell engulfs large particles or whole cells
Pinocytosis
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
receptor-mediated endocytosis
when receptors on the outside of the cell membrane bind to specific substances outside the cell and take them in
Exocytosis
Process by which a cell releases large amounts of material by attaching a vesicle to the cell membrane
water potential
the potential energy of a volume of water, expressed as a pressure
Water potential’s relationship to solute concentration
inversely proportional
How water travels
from low to high potential
relationship between water potential and pressure
directly proportional
solute potential equation
Ψs = -iCRT
R in solute potential equation
Pressure constant (0.0831 liter bars/mole K)
Relationship between solute potential and solute concentration
Higher solute concentration = lower solute potential
relationship between solute potential and water potential
directly proportional
cell size and diffusion
smaller cell - higher diffusion rate
