YEAR 9 – Topic 3 – Movement In And Out Of Cells And Biological Molecules Flashcards
What is diffusion?
Diffusion is the movement of particles from an area of high concentration to low concentration. Particles move down a once traction gradient. It is a passive process (doesn’t require energy).Eg. CO2 moving in and out of a leaf.
In diffusion…
Molecules move down a concentration gradient.
Diffusion does NOT need….
– Energy
– Membranes
What factors affect the rate of diffusion?
– Temperature (temp increase, particles gain more energy, move faster, speed up the rate)
– Concentration gradient(steeper concentration gradient = faster diffusion)
– Surface area of membrane (larger= more particles can go through the membrane)
– Diffusion distance (smaller distance = quicker because less space for particles to move through).
- How much space there is in the container
Give an example of diffusion in living and non-living systems :
Living: water/ oxygen moving in and out of a plant cell.
Non-living: perfume being sprayed into a room.
What is osmosis?
Osmosis is the movement of water particles from an area of high water concentration to low water concentration through a partially permeable membrane. Eg. Water moving in and out of a cell.
In osmosis…
Water moves down a concentration gradient from a high concentration OF WATER to a low concentration OF WATER
What does osmosis require?
Water and a partially permeable membrane with a concentration gradient across it
Osmosis does NOT require…
Energy
Give an example of osmosis in living and non-living systems :
Living: potato cylinders
Non living: visking tube
What factors affect the rate of osmosis?
Temperature, concentration gradient, surface area and space that it perform osmosis over.
What is active transport?
The movement of particles from an area of low concentration to an area of high concentration, using energy.
Active transport DOES need…
Energy
Molecules in active transport…
Move AGAINST (up) a concentration gradient.
What factors affect the rate of active transport?
Temperature, concentration gradient, surface area and space that it transport over.
Active transport does NOT need…
A membrane
What chemical elements are present in carbohydrates?
Carbon, Hydrogen and Oxygen.
What is the structure of carbohydrates?
Polymers (long chains of amino acid monomers)
Which carbohydrates are Monosaccharides?
– Glucose
– Fructose
– Galactose
What is glucose? Include... What type of sugar it is What its chemical formula is And what it looks like!!!
Glucose is a monosaccharide.
This means it is the simplest form of sugar.
Chemical formula is C6H12O6
<=> like a squashed hexagon!!!
How do you test for glucose?
What do positive and negative results look like?
- Put some glucose solution into a test tube.
- Add a few drops of Benedict’s Solution.
- Put the test tube into a beaker of hot/boiling water.
Positive = Brick red precipitate
Negative = Blue solution (no precipitate)
What carbohydrates are disaccharides?
– Maltose
– Sucrose
– Lactose
What is a disaccharide?
It is two monosaccharides joined together.
Name the two sugars that make up Sucrose…
Glucose + Fructose
Name the two sugars that make up Maltose…
Glucose + Glucose
Name the two sugars that make up Lactose…
Glucose + Galactose
What is starch’s function in nature?
– Plants use starch as an energy source.
– Animals break down starch to get energy.
What is the function of starch in our diet?
Starch is a source of sugar, and hence energy, in an animal’s diet.
What is the solubility of starch?
Starch is insoluble in water unless it has been heated up.
How do you test for starch?
What do positive and negative results look like?
- Put some starch solution in a test tube
- Add a few drops of iodine
Positive = Blue Black
Negative = Orange/Brown
What is a polysaccharide?
Polysaccharides are carbohydrates that are made up of monosaccharides or disaccharides.