Biology 1 Lipids, membranes and cholera Flashcards
What chemical elements make up lipids?
Carbon, Hydrogen, Oxygen
What is the structure of a triglyceride?
3 fatty acids and one unit of glycerol
What makes a lipid unsaturated
Contains C=C
How is the structure of phospholipids different to triglycerides?
One fatty acid is removed and replaced by a phosphate group.
What are the bonds between fatty acids called?
Ester bonds
Fatty acid tails are…
Hydrophobic
Phospholipid heads are…
Hydrophillic
What molecules can pas through the plasma membrane?
Water, Carbon dioxide, Oxygen, Fat/ lipid soluble
What model shows the contents of a plasma membrane?
Fluid Mosaic Model
What molecules does a cell membrane consist of?
Protein, Carbohydrates and Phospholipids.
What do channel proteins do?
Allows ions and polar molecules to pass through the membrane.
Which processes allow substances to pass across the cell membrane?
Diffusion, Facilitated diffusion, Osmosis, Active Transport.
What do glycoproteins do?
Cell recognition
What do carrier proteins do?
aid the transport of ions and polar molecules across the membrane by active transport and facilitated diffusion.
Factors that affect rate of diffusion
Temperature, Concentration, Surface Area, Thickness of exchange surface
Diffusion
The net movement of molecules from a high concentration to a low concentration until they are equally distributed.
What substance does facilitated diffusion allow to pass through the membrane and how does it happen?
Hydrophillic sustances by carrier proteins. Does not require ATP
facilitated diffusion reaches a saturation point
What does adding a solute to water do to the water potential?
Lowers the water potential
Fick’s law
Diffusion Distance
Osmosis
Net movement of water molecules from a solution with a higher water potential to a solution with a lower water potential across a partially permeable membrane
Isotonic solution
has same water potential as surrounding solution so no net movement of water
Active Transport
Movement against concentration gradient
Requires carrier proteins
That require ATP
Mark points for Co- transport and how oral rehydration solutions work
- Glucose and sodium enter cell via facilitated diffusion
- Sodium moves into blood via active transport
- Glucose moves into blood via active transport
- Lowers water potential of blood
- Water moves into blood leading to rehydration
How do cholera bacteria cause illness
- Burrow into lining of small intestine and release toxins.
* Toxins cause massive increase of active transport of ions into the lumen of the small intestine.
Mark points for how cholera cause illness
- Ions move into small intestine
- Lower water potential of lumen
- Water move from high to low by osmosis
- Into small intestine causing diarrhoea which leads to dehydration
What are the contents of oral rehydration solutions?
salt, potassium chloride, sodium hydrogen carbonate and glucose
