B2 form and function of cells Flashcards
integral protein
definition
protein embedded through the whole plasma membrane due to their amphipathic nature
peripheral protein
definition
proteins bound to the inner or outer surface of the membreane or integral protein
cholesterol
definition
a chain of steroid lipids that sit in the hydrophobic regions of animal cell membranes
glycoprotein
definition
carbohydrate attached to a protein
glycolipid
definition
carbohydrate attached to a lipid
junction membrane protein
definition/function
joins two cells together
enzyme membrane protein
definition/function
catalyse metabolic reactions
transport membrane protein
definition/function
faccilitated diffusion, osmosis and active transport
recignition membrane protein
definition/function
glycoproteins, markers for cell identification
anchoring membrane proteins
definition/function
attachment site for cytoskeleton
transduction membrane protein
definition/function
receptors for hormones and other signalling molecules
what happens to plasma membranes in cold environments
condensing of phospholipids reduces membrane fluidity
solution to cold environments for plant plasma membranes
unsaturated fats to preserve distance
solutions to cold environments for animal plasma membranes
unsaturated fatty acids and cholesterol preserve distance
what happens to a plasma mambrane under hot conditions
expands and can lyse/burts
solutions for plant plasma membranes in hot environments
more saturated fats for denser phospholipids and higher melting points
solutions for animal plasma membranes in hot environments
cholesterol to connect and reduce space between phospholipids
simple diffusion
definition
particles move through the phospholipid bilayer from high concentration to low concentration
simple diffusion moves what molecules
fast: small, non-polar
slowly: small and polar
facilitated diffusion
definition
particles move from high concentration to low concentration through a protein channel or carrier protein
protein channel moves what particles
small charged/polar things
carrier protein moves what molecules
larger polar/non-polar things
osmosis
definition
movement of water form a high concentration of water to a low concentration of water through the plasma membrane or aquaporins
protein pump is used for
moving any particle from alow concentration to a high concentration
properties of passive transport
- movement from high concentration to low concentration
- down or with the concentration gradient
- NO energy required
types of passive transport
- simple diffusion
- facilitated diffusion
- osmosis
properties of active transport
- from a low concentration to high concentration
- up or against the concentration gradient
- requires energy (ATP)
types of active transport
- protein pumps
- endo/exocytosis
hypertonic environment
definition
an aqueous solution with a higher solute concentration than other (the cell cytoplasm)
hypotonic envirionment
definition
an aqeous solution with a lower solute concentration compared to another (the cell cytoplasm)
isotonic environment
definition
when two solutions have the same solute concentration (intra and extracellular environment)
endocytosis
definition
materials enter the cell by pushing through the plasma membrane, creating a vessicle
type of active transport
exocytosis
definition
meterials exit the cell by a vessicle during with the membrane expelling them
type of active transport
gated ion channel
definition
protein channels specifically for ions that do not remain open naturally
indirect active transport
definition
when ATP is used to move a substance but a second substance can move as a result of this
Cell-Adhesion molecules (CAM)
definition
proteins embedded into the cell membrane that protrude out and join to create cell junctions
voltage gated ion channel
definition
an ion channel whose activity relies on the chanrge difference between the inside and outside of a cell
example of a voltage gated ion channel
potassium channel
neurotransmitter gated ion channel
definition
an ion channel whose activity is determined by receptors on the protein channel that only open when a specific neurotransmitter binds to it
example of a neurotransmitter gated ion channel
nicotonic acetylcholine receptor
example of indirect active transport
explain
sodium-dependent glucose cotransporters
matrix
definition
the fluid area of enzymes inside the inner membrane of the mitochondria
site of the Kreb’s cycle
cristae
definition
tubular regions created by deep folds in the inner membrane of the mitochondria
thylakoid
definition
disks of membrane that stack to form granum and are often connected by lamella in chloroplasts
stroma
definition
the aqeous cytoplasm-like fluid surrounding the thylakoids in chloroplasts
site of kelvin cycle
cisternae
definition
the stacked flatterned sacs that make up the golgi
clathrin
definition
protein that anchors specific proteins to areas of the cell membrane
morphogen
definition
signal molecule that controls cell differentiation
stem cell
definition
undifferentiated cells that can become multiple different types of specialised cells
stem cell niche
definition
the location in adults where multipotent stem cells are present in high numbers as a result of regular proliferation
steps from gamete to infant
gamete, zygote, embryo, foetus, infant
unique properties of stem cells
- they can self renew
- can recreate functional tissues
totipotent stem cells
definition
can produce any tissue type, only found in zygotes
pluripotent stem cells
definition
can differentiate into MOST cell types
multipotent stem cells
definition
can differentiate into manu similar cell types
where are totipotent stem cells found
zygotes (3-5 day embryos)
where are pluripotent stem cells found
embryos (days 4-7)
where are multipotent stem cells found
adults and everything up to adults
what does a low concentration or morphogens form
nerve cells
what does a medium concentration of morphogens differentiate into
muscle cells
what does a high concentration of morphogens differentiate into
epidermal cells
adaptation of size for egg cell
higher volume means more storage for nutrients so smaller surface area to volume ratio
adaptation of size for sperm cells
slender and small volume for increased speed
adaptations of red blood cells for size
biconcave shape means higher SA:V and more available haemaglobin
adaptations of size for white blood cells
more rough endoplasmic reticulum and golgi for antibodies when swollen
adaptations of sized for neurons
long axon for increased transmission speed
striated muscle
more force and flexibility
erythrocytes adaptations for surface area
- low volume due to no nucleus and shape
- more cytoplasm with haemaglobin close to membrane
- O2 moves in and out faster
proximal convoluted tubule cells adaptations for surface area
- cube shape to pack together tightly
- microvilli on inside surface
- folds and protective layer on outer surface
- mitochondria for active transport
type 1 pneumocytes adaptations for surface area
- long and thin cells with few organelles
- only one cell thick and near one cell thick capillaries
- tight junctions to keep fluid out
what constitutes an organelle
an organelle is a discrete subunit of a cell that performs one or more specific functions
type 2 pneumocytes adaptations for surface area
- cube shape with more volume for organelles
- room for organelles to make and secrete surfactants
- microvilli facing alveolus
skeletal muscle cells adaptations for surface area
- long multinucleate cells created from cells fusing together
- visible bands so striations shorten and lengthen for movement
cardiac muscle cells adaptations for surface area
- branching to connect multiple cells in y shape
- intercalated disks form junctions between cells to pass electrical currents
