TERM 1 BIOLOGY- Sem 1 24'

A1 Water, D2.3 Water Potential, B2.1 Membrane structure and transport, A2.2 Cell Structure

phospholipids spontaneously form vesicles due to

hydrophilic and hydrophobic properties

hypertonic solutions can damage human cells by

dehydrating them

example of a medical isotonic sodium chloride solution

normal saline

normal saline can be used for

rinse wounds, basis for eye drops, frozen for cooling organs, introduced into patient’s blood system via intravenous drip

used medical procedures so cell stay healthy

isotonic solutions

hypotonic solutions can cause human cells to

swell and burst

membrane structure

magnification formula

image size/ actual size

spontaneous formation of vesicles helped

the first cell form a compartmentalised region, semi-permeable

polar covalent bond

unequal sharing of electrons

cohesion

water molecules stick together due to hydrogen bonding

adhesion

water sticking to a solid surface in the form of capillary action

water as a solvent

can only dissolve hydrophilic things such as polar molecules or ions

physical properties of water

buoyancy, viscosity and thermal conductivity

example of water being a good thermal conductor

water is good at maintaining body temperature

osmosis

passive movement of water from low concentration to high concentration

passive

no energy required

isotonic

same concentration

hypotonic

lower concentration

hypertonic

higher concentration

aquaporin

channel protein that allows water to pass through more easily

plant cells have a

cell wall that prevents excess water

animals have

no cell wall

what do other eukaryotes do when they have no cell wall

they have adaptations

turgid

plants are in hypotonic medium

flaccid

when pressure inside drops to atmospheric levels

plasmolysis

in hypertonic solution, membrane shrinks away from cell

lysed

cell bursts in hypotonic solution

shriveled

shrinks in hypertonic solution

normal

when in isotonic solution

the lipid bilayer

two layers of lipids, controls what enters and leaves the cell

larger molecules are

not as permeable

membrane is not permeable

to polar/charged particles

diffusion

passive movement from high concentration to low concentration

JETRAT

junction, enzymes, transport, recognition, attachment, transduction of hormonal signals

integral proteins

transmembrane proteins, full length of bilayer

peripheral proteins

only attached to the surface

facilitated diffusion

movement of particles from area of low concentration to high concentration through a channel protein

active transport

movement of particles from low concentration to high concentration, requires energy

glycoprotein

protein + carbohydrate, chain extending outside, important for recognition and joining of cells

glycolipids

liquids + carbohydrates, sticking outside, important to eukaryotes and recognition in immune system

fluidity

how easily something can move around

saturated fatty acids

less fluid than unsaturated fatty acids

osmosis

diffusion of water or other solvents through a semipermeable membrane

endocytosis

process of bringing material into the cell by engulfing it

endocytosis process

IPF

IPF definition

indentations, pinches off, forms a vesicle

vesicles are used in the cell to transport

SWFM

SWFM definition

protein synthesis by ribosomes, wrapped in a vesicle, fuses with golgi membrane, golgi modifies it and repackages

exocytosis

process of moving material out of the cell

exocytosis process

OIF

OIF definiton

materials out of the cell, inside a vesicle, fuses with membrane

cell growth process

GPFB

GPFB

membrane growth, vesicles pinch off, fuse with membrane, results in bigger membrane

what bonds are responsible for the cohesive properties of water molecules

hydrogen bonds between water molecules

most enzyme molecules are

hydrophilic and soluble

water molecule diagram

oxygen = slightly negative, hydrogen= slightly positive

why are lipid tails hydrophobic

they and insoluble and non-polar and they provide a barrier between the cell, cytoplasm and external liquids

what is an animal example of buoyancy

black throated loon being able to float on water with feathers

what is an animal example of thermal conductivity

polar bears keeping warm in cold air with better insulation

what is an animal example of low viscosity

animals are more easily able to move in water

what causes rates of diffusion to differ

different concentration gradients at the start

uptake of water by cells in the wall of the intestine and loss of water from a plant cell in a hypertonic environment are

processes that occur by osmosis

cell walls are

structures only found in prokaryotic cells

water molecules are highly cohesive which is

important for transport in xylem

where do hydrogen bonds form

between the slight positive charge of hydrogen and slight negative charge of oxygen in different water molecules

nucleus

Rough ER

Smooth ER

Golgi App

Lysosome

Mitochondrion

free ribosomes

chloroplast

vacuoles and vesicles

microtubules and centrioles

cytoskeleton

cilia and flagella