BIOLOGY 3 Flashcards
Diffusion.
The movement of small molecules from a high concentration to a low concentration down a concentration gradient through gaps in a membrane and its a passive process.
Active transport
The movement of substances, through a partially permeable membrane, against the concentration gradient and it requires energy from respiration.
Osmosis
The movement of water, through a partially permeable membrane, into a solution with a lower water concentration
Partially permeable membrane
a membrane which allows water and other small molecules to pass through, but not larger molecules such as starch.
Flaccid
Lacking in stiffness or strength. Soft and floppy.
Emulsification
Breaking down large droplets of fat into smaller ones.
Enzymes
proteins that act as biological catalysts (they speed up reactions without being used up)
Denatured
when the shape of an enzyme’s active site changes so that the enzyme no longer works
Artery
blood vessels that carry blood away from the heart and towards an organ.
What does an artery look like?
Thick walls and small lumen to help maintain pressure of blood.
Vein
Blood vessels that carry blood back to the heart from an organ.
What do veins look like?
Thin walls, large lumen and valves to stop backflow of blood.
Valve
Short flaps which ensure blood only flows in one direction.
Lumen
Space inside a blood vessel.
What reagent is used to test for starch?
Iodine solution.
True or False: Benedict’s solution is used to test for glucose.
True.
Fill in the blank: The reagent used to test for proteins is called __________.
Biuret solution.
Which reagent is used to test for lipids?
ethanol
What color change indicates the presence of starch when using iodine solution?
Blue-black.
Multiple choice: What is the initial color of Benedict’s solution before testing for glucose? (A) Blue (B) Red (C) Green (D) Yellow
A) Blue.
What is the expected color change of Benedict’s solution when glucose is present?
Brick red.
True or False: Lipids can be tested using the Emulsion test.
True.
What is the main purpose of using Biuret solution in food testing?
To detect the presence of proteins.
Fill in the blank: A positive test for lipids will show a __________ stain.
Red.
