AOS1 Flashcards
Simple Diffusion.
Movement of substances from a high concentration to a low concentration
Facilitated Diffusion.
Molecules that cross through a membrane via a specific transmembrane integral protein.
Osmosis
Passive movement of free water molecules from a low concentration of solute to a high concentration of solute through a semi-permeable membrane.
Active transport.
Requires energy –> movement in and out of the cell.
Passive transport
doesn’t require energy –> movement in and out of the cell.
Bulk Transport.
Type of transport that uses vesicles to move large molecules or groups of molecules in or out of the cell.
Exocytosis
Moves large substances out of the cell.
Endocytosis
Moves large substances into the cell.
Hypertonic
Movement OUT of the cell - to a higher concentration of solute.
Isotonic
Movement IN and OUT of the cell - equal in concentration.
Hypotonic.
Movement going INTO the cell - to a high concentration of solute
Hydrophobic
Hates water.
Hydrophilic
Loves water.
Extracellular
Outside of the cell In contact with the plasma membrane; fluid
Intracellular
Inside the cell; contact with the plasma membrane
Solute
Substances that dissolve in a solvent
Solution
Substance that a solute dissolves in.
Function of the plasma membrane.
- Transport.
- Communication.
- Retains contents.
- Surrounds organelles.
Phospholipid bilayer.
2 layers of phospholipid that make up a cell membrane.
Fatty acid tails.
Hydrophobic - non-polar.
Phospholipid head.
Phosphate-containing head.
Hydrophilic - polar.
Polar
Charges are different at each end.
Non-Polar
Same charges.
Channel Proteins
Create holes (hydrophilic) in the cell membrane, enabling transport of molecules DOWN a concentration gradient.
Carrier Proteins
Integral proteins, transport chemicals across the membrane. UP and DOWN concentration gradient.
Integral proteins.
Permanent part of the membrane controls the movement of molecules across them.
Cholesterol
A molecule that is lipid-based and regulates the fluidity of the membrane.
Transmembrane proteins
extend from one end of membrane to other.
Carbohydrates
- involved in signally and adhesion.
- part of glycolipids or glycoproteins.
- can be attached to proteins or phospholipids.
Peripheral temporary proteins.
Intact with only the hydrophilic heads of a phospholipid.
Cell Membrane.
phospholipid bilayer that encloses the contents of a cell. Controls the passage of substances in and out of the cell.
Osmolarity
the total concentration of solutes in a solution.
Semi-membrane permeability.
means some substances can pass through whilst others cannot.
Factors that affect diffusion across a membrane.
- size
- tonicity
- temperature
- hydrophobic/hydrophilic
- polarity
Concentration gradient
the difference in solute concentration between adjacent areas.
The difference in concentration on two sides of a membrane.
How does surface area to volume affect the diffusion of molecules into the cell?
The larger the surface area to volume (being smaller cells), the greater chance of diffusion.
Why are cells so small?
Cells are small so diffusion can occur to absorb nutrients, efficiently and quickly.
Aim
What you’re investigating.
Hypothesis
If….then…because..
Independent variable
What is being changed.
Dependent variable
What is being measured.
Controlled variable
What stays the same.
Conclusion.
Approve/Disprove hypothesis.
Endoplasmic reticulum
.
Golgi apparatus
.
Secretory vesicle
.
Phagocytosis.
Endocytosis of a solid material; bacteria.
Pinocytosis.
Endocytosis of a fluid material; lipid.
