Chapter 3 Flashcards
Functions of a cell
- cell metabolism
- Synthesis of molecules
- Communication
- Reproduction and inheritance
Outside of membrane is more ___ charged
positively
Plasma membrane made of
glycocalx (carbs and lipids and proteins on surface)
what lipids make up the membrane
phospholipids and cholesterol
Phospholipid Bilayer
Polar (hydorphilic ends) face water on interior and exterior while non polar tails inward
cholesterol of membrane
interspersed between phosphoplids
amount determine fluid nature of membrane
fluid nature of membrane allows
distribution of molecules within membrane
membranes can fuse with eachother
phoshoplipids automatically reassemble if damaged
integral protein membranes
extend deep into membrane often from one end to another
peripheral protein membranes
attach to integral protiens at inner or outer surfaces
marker molecules
glycoprotiens or glycolipids
allow cells to identify one another or other molecules
transport proteins characteristic
specificity–single type of molecules
competition–molecules of similar shape can bind
saturation–rate of transport limited to number of available carrier proteins
Leak Ion Channels
Always open
responsible for permeability of ion membrane when ion membrane is at rest
Gated Ion Channels
open or closed by certain stimuli
Ligand gated channel
open in response to small molecules that bind to proteins or glycoprotiens
Voltage gated
open when there is a change in charge across plasma membrane
Carrier proteins (ie transporters)
integral protien that moves ions from one side to another
have specific binding sites
changes shape to transport ion and then resumes original shape
uniporters
moves one ion/molecule
symporter
moves two ion/molecule in same direction
Antiporter
moves two ion/molecule in OPPOSITE direction
ATP powered pumps
requires ATP to function
use of energy allows cells to accumulate substance
rate depends on concentration of substrate and ATP
Receptor proteins
have exposed receptor site
can attach to specific chemical signals
enzymes
catalyze reactions on outer and inner surface of membrane
3 types of Passive membrane transport
- diffusion
- osmosis
- facilitated diffusion
2 types of Active membrane transport
active transport
secondary active transport
vescular transport
endocytosis and exocytosis
diffusion
brings solutes from area of higher concentration to area of lower concentration in a solution
osmosis
movement of water across a selectively permeable membrane
moves from low concentration of solutes to high concentration of solutes
isomotic
solutions with same concentration of solute particles
hyperosmotic
solution with greater concentration of solutes
hyposmotic
solution with lower concentration of solutes
isoTONIC
cell neither shrinks or swells
hypertonic
crenation
hypotonic
lysis–cell swells
facilitated difussion
mediated transport carried out by channel/carrier protiens–no ATP
Active transport
requires ATP
can be moved against concentration gradient (low to high) and allows substances to accumulate on side of cell
rate depends on concentration of substrate and concentration of ATP
secondary active transport
used primary active transport
phagocytosis
solid particles ingested and large vesucle is formed
requires ATP
“eating”
Pinocytosis
disolved molecules ingested and small vescule is formed
microtubules
hollow tubes made of tubulin that act as:
-internal scaffold of cell
transport and cell division
actin filaments
help with structure,
support microvilli
contractility
movement
intermediate filaments
help with mechanical strength
