SB1 Flashcards
Key concepts
Name the sub-cellular structures in animal cells
- Cell membrane
- Cytoplasm
- Nucleus
- Ribosomes
- Mitochondria
Name the sub-cellular structures in plant cells
- Cell wall
- Cell membrane
- Cytoplasm
- Nucleus
- Ribosomes
- Mitochondria
- Vacuole
- Chloroplasts
Name the sub-cellular structures in bacteria cells
- Cell membrane
- Ribosomes
- Cytoplasm
- Chromosomal DNA
- Plasmid DNA
- Flagella
What type of cell are plant and animal cells
Eukaryotic
What type of cell are bacteria cells
Prokaryotic
What is the function of the cytoplasm
- Where chemical reactions take place
- Site of anaerobic respiration
What is the function of the nucleus
- Contains all of the cells genetic information
What is the function of mitochondria
- Site of aerobic respiration
What is the function of ribosomes
- Protein synthesis
What is the function of the cell wall
- Maintains cell structure
- Made of cellulose
- Keeps cell rigid
What is the function of the cell membrane
- Controls what enters and leaves the cell
What is the function of chloroplasts
- Absorb sunlight
- Site of photosynthesis
What is the function of the vacuole
- Helps maintain cell structure
- Holds cell sap
What is the function of chromosomal DNA
- Holds bacteria’s necessary genes for survival and reproduction
What is the function of plasmid DNA
- Holds bacteria’s extra genes e.g. antibiotic resistance
What is the function of the flagella
- Helps propel bacteria
- Helps bacteria move
Define enzymes
- Biological catalysts that help speed up a reaction without getting used up
Why are enzymes imprtant
- Help reduce the need for high temperatures to speed up reaction
- Less likely to cause damage to cells
- Requires less energy
- Very specific
What are enzymes
Large proteins
What are the two things enzymes do
- Break down one large substrate into tiny products
- Join together lots of tiny substrates into one big product
What is the key feature of the active site
It is complementary to the substrate
What is the difference between the ‘Lock and key’ theory and the ‘Induced fit’ theory
- Lock and key depicts that the substrate fits perfectly into the active site
- Induced fit states that the active site will change shape to perfectly fit substrate
What is the optimum pH for body enzymes
7
What types of enzymes have a different optimum pH
Stomach enzymes
What is the optimum temperature for body enzymes
37 degrees
What is the purpose of digestive enzymes
To break down larger food molecules into smaller more soluble ones that can be absorbed through the small intestine
Function and location of amylase
- Breaks down starch into sugars e.g. maltose
- Small intestine
- Pancreas
- Salivary glands
Function and location of protease
- Breaks down proteins into amino acids
- Pancreas
- Small intestine
- Stomach
Function and location of lipase
- Breaks down fats into glycerol and fatty acids
- Pancreas
- Small intestine
What are specialised cells
- Cells that have differentiated to adapt to a certain function
Function and adaptations of a sperm cell
- Deliver genetic material to an egg cell to fertilise it
- Fertilisation and reproduction
- Has 23 chromosomes in its (haploid) nucleus
- Flagellum allows sperm cell to swim through uterus
- Lots of mitochondria to provide energy for swimming
- Streamlined shape
- Acrosome contains digestive enzymes which help break down eggs jelly coat
Function and adaptations of an egg cell
- Fertilisation and reproduction
- Has 23 chromosomes in its (haploid) nucleus
- Cytoplasm contains necessary nutrients for embryo growth
- Jelly coat hardens to prevent more than one sperm cell entering
Function and adaptations of a ciliated epithelial cell
- Line surface of organs to help move substances e.g. mucus in one direction
- Cilia on their surfaces
Describe the food test for reducing sugars
- Benedict’s test
- 5ml of food sample mixed with 10 drops of benedict’s solution (blue)
- Place test tube in water bath at 75 degrees
- If reducing sugars are present, precipitate will turn green, yellow or brick-red depending on concentration
Describe the food test for proteins
- Biuret test
- Prepare 2ml of food sample then add potassium hydroxide (to make it alkaline)
- Then add copper sulphate
- If solution turns pink/purple protein is present
Describe the food test for lipids
- Ethanol emulsion test
- Prepare 5ml of unfiltered food sample
- Add 2ml of ethanol and vigorously shake
- Add 2ml of distilled water
- If it turns cloudy lipids are present
Describe the food test for starch
- Iodine test
- Prepare 5ml of food sample
- Add iodine
- If it turns blue black, starch is present
