Test one Flashcards
what are prokaryotic cells?
Bacteria and archaea
Eukarya
Plants and Animals
selectively permeability
controlled passage of ions and molecules into the cell
hypertonic
higher concentration of a solution
Hypotonic
lower concentration of solutes
isotonic
same concentration of solutes
osmosis
diffusion of water across a permeable membrane
Simple diffusion
movement of ions and molecules from an area of high concentration to an area of low concentration
3 tenets of cell theory
1,. all living organisms are composed of one or more cells
2. Cells are the smallest units of life
3. new cells come from pre-exisiting cells
4 basic features of a cell
plasma membrane
nucleic acids
ribosomes
carbohydrates
Why are smaller cells more efficient?
higher surface area to volume ratio
What is in the endomembrane system
nuclear envelope, smooth and rough ER, Golgi apparatus, lysosome, Peroxisome, vacuole
organic molecules
carbon containing molecules
polymers
molecules made of smaller units called monomers
how are polymers put together
dehydration reaction
how are polymers broken apart
hydrolysis reactions
protein monomer
amino acids
nucleic acids monomer
nucleotide
lipid monomer
fatty acids
phospholipids
amphipathic molecules, containing hydrophobic and hydrophilic regions
steroids
hormones including:
estrogen
testosterone
progesterone
amphipathic
having both a hydrophilic region and a hydrophobic region
Covalent bond
shared electrons
ionic bond
atom that accepts 1 electron that another atom donates
polar-covalent bond
atoms are shared unequally in a covalent bond
highest difference in between atoms
non-polar covalent bonds
equal sharing of electrons
hydrogen bonds
weak attraction between a hydrogen atom and another atom
saturated fatty acids
all carbon atoms form only single covalent bonds
solid at room temp
primarily in animals (butter)
unsatterated fatty acids
one double covelant bond
between carbon atoms
liquid @ room temp
primarily in plants (oil)
phospholipid bilayer
a double membrane including polar hydrophilic heads and two non-polar hydrophobic fatty acid tails
fluid mosaic model
model of the plasma membrane of phospholipids that are free to move sideways within a lipid bilayer
which way can phospholipids move?
laterally, turn in place
fluidity
movement of phospholipids
permeability
ability of molecules to pass through a lipid bilayer
more movment =
more fluidity
more fluidity =
more permeability
what factors affect fluidity?
length of fatty acid tails,
fatty acid saturation,
temperature
length of fatty acid tails
shorter tails have a higher fluidity
fatty acid saturation
unsaturated tails are less fluid
higher temperature =
higher temp = higher fluidity
cholesterol in animal cells at freezing temp
high concentration prevents the membrane from freezing
(increases fluidity)
cholesterol in animal cells at high temp
high concentration decreases fluidity
what factors influence permeability?
size, charge
true or false:
non polar molecules are able to pass freely
true
what has high permeability?
gases
ex: O2
What has moderate permeability?
water
H2O
What has low permeability?
polar organic molecules
ex: glucose
what has extremely low permeability?
any ion, charged, polar molecules
ex: proteins, nucleic acids, Na+
membrane transport
movement of substances across a biological membrane
passive transport
the movement of substances across a cell membrane without the use of energy
active transport
the movement substances across a cell membrane, assisted by transport proteins and requiring energy
Moves from low concentration to high concentration
primary active transport
Uses transporter protein that undergoes a conformational change, relying on ATP
Builds electrochemical gradient
secondary active transport
Uses a transporter protein to move substances against electrochemical gradient
Energy comes from the charged molecules
facilitated diffusion
the movement of specific molecules across a cell membrane through protein channels
What are the three major structural components of an amino acid?
Side chain (R)
Amino group
Carboxyl group
What are the four main elements found in all proteins?
Oxygen
Carbon
Hydrogen
Nitrogen
The covalent bond that joins two amino acids is called a _______ bond.
peptide
The amino acid sequence of a polypeptide is called the ___ structure
primary
channel
Transport protein
Allows passage of ions/molecules
Can open and close
Transport protein
Provides passage for ions and hydrophilic molecules
To kill a slug you pour table salt on it, the salt forced the water out of its cell and the animal dies. Water moved out of the cell through __ because they were placed in an environment that is __ to the inside.
Osmosis, hypertonic
Transporter proteins
Proteins that undergo a conformational change, allowing molecules to enter the cell and allowing waste to be expelled
How does a transporter protein work?
The conformational change is triggered when a solute enters the pocket, and is opened to the other side
What is a conformational change?
Change in shape triggered by contact
