Chapter 5 Flashcards
What is the structure of the cell membrane
Fluid mosaic
what do hydrophobic tails mean
water strays away
the membrane of a cell is mostly made up of what
phospholipids and proteins, (glycolipids)
what are phospholipids
they are fats, they have hydrophilic heads and hydrophobic tails
what does the fluid mosaic model mean?
the membrane is flexible and made up of multiple proteins
What does selectively permeable mean
it selects what can enter and leave the cell
a cell being selectively permeable allows the cell to remain
balanced (homeostasis)
list the main functions of proteins on the cell membrane (6)
- Intercellular joinings
- Enzymatic Activity
- Transport (active/passive)
- Cell-Cell Recognition
- Anchorage/attachment
- Signal Transduction
What is passive transport
transportive molecules without any energy
What are the different types of passive transport
Diffusion, osmosis, facilitated diffusion
What is diffusion
when molecules move through the phospholipid bilayer from an area of high to low concentration to form an equilibrium
Do molecules move down or up the concentration gradient with diffusion
down
what is the concentration gradient
the amount of molecules that are present
What is equilibrium
when there is equal movement in both directions across a membrane
what is osmosis
the movement of water
with osmosis where do water molecules move
from an area of HIGH solute concentration to an area of LOW solute concentration
what is hypotonic
when water moves into the cell (making it bigger and burst)
what is isotonic
when water moves in and out of the cell in equal rate (ideal)
what is hypertonic
when water moves out of the cell (making it shrink)
what is facilitated diffusion
when molecules move through the cell membrane with the help of proteins
There are 2 types of protein, what are they
protein channel and carrier proteins
what are protein channels
a tunnel that lets molecules pass through
what are carrier proteins
they change shape to allow molecules through
What does active transport use
energy
what is active transport
molecules move from an area of low concentration to an area of high concentration with energy
do molecules move up or down the concentration gradient using active tranport
up
what is endocytosis
when molecules enter the cell via vesicles
what is pinocytosis in endocytosis
small solutes/liquids
what is phagocytosis in endocytosis
large food particles
what is exocytosis
molecules exiting the cell via vesicles
high –> low
diffusion
low solutes –> high solutes
osmosis: water
low –> high
active transport
particle movement from high concentration —> lower concentration
passive transport
