B1 Flashcards
Key Concepts
What are the 2 types of cells?
Prokaryotic (plants & animals) and eukaryotic (bacteria).
Which 3 subcellular structures of a plant cell does an animal cell not have?
Vacuole, chloroplasts, cell wall.
What are the 2 types of microscopes?
Light microscopes and electron microscopes.
Why are electron microscopes better than light microscopes?
They have a max. magnification of x1,000,000 and they have a high resolution.
What are the 2 theories of enzymes?
“Lock-and-key” theory and “induced-fit” theory
Explain both models.
Lock and key is when the substrate is complementary to the enzyme. Induced fit is when the enzyme changes shape to fit the substrate.
What are the digestive enzymes?
Carbohydrase/amylase, protease and lipase.
What 3 factors can affect the rate of reaction?
Temperature, pH and the amount of substrate.
What are the 3 types of transport?
Diffusion, osmosis and active transport
What is diffusion?
The movement of particles from high to low concentration.
What is osmosis?
The movement of water particles from high to low concentration across a partially permeable membrane.
What is active transport?
The movement of particles from low to high concentration across a membrane using energy from respiration.
What are the 2 calculations associated with microscopy?
1) magnification = image size × actual size
2) total magnification = eyepiece lens × objective lens
What are the 4 food tests?
1) Emulsion test - for lipids
2) Biuret test - for proteins
3) Benedict’s reagent - for sugars
4) Iodine test - for starch
What are the signs in these tests?
1) Emulsion test - becomes cloudy if lipids present
2) Biuret test - becomes purple if proteins present
3) Benedict’s reagent - becomes green to red (depending on the concentration) if sugars present
4) Iodine test - becomes blue-black if starch present
