Topic 1: Cell Biology Flashcards
What are the two types of cells?
● Eukaryotic (plant and animal)
● Prokaryotic (bacteria)
What are the differences between eukaryotic and prokaryotic cells?
Prokaryotic cells are much smaller than eukaryotic cells.
Eukaryotic cells contain membrane bound-organelles and a nucleus containing genetic material, while prokaryotes do not.
What is the prokaryotic cell wall composed of?
Peptidoglycan
How is genetic information stored in a prokaryotic cell?
Found free within the cytoplasm as:
● Chromosomal DNA (single large loop of circular DNA)
● Plasmid DNA
What are plasmids?
● Small, circular loops of DNA found free in the cytoplasm and separate from the main DNA.
● Carry genes that provide genetic advantages e.g. antibiotic resistance.
What is order of magnitude?
A power to the base 10 used to quantify and compare size.
What is a centimetre (cm)?
1 x 10-2 metres
What is a millimetre (mm)?
1 × 10-3 metres
What is a micrometre (µm)?
1 × 10-6 metres
What is a nanometre (nm)?
1 x 10-9 metres
What is the difference in order of magnitude between a human hair (length = 100 µm) and the HIV virus (length = 100 nm)?
100 µm = 10-4 m
100 nm = 10-7 m
-4-(-7) = -4 + 7 = 3
List the components of both plant and animal cells
(5)
- Nucleus
- Cytoplasm
- Cell membrane
- Mitochondria
- Ribosomes
List the additional cell components found in plant cells (3)
- Chloroplasts
- Permanent vacuole
- Cell wall
Other than storing genetic information, what is the function of the nucleus?
Controls cellular activities
Describe the structure of the cytoplasm
- Fluid component of the cell.
- Contains organelles, enzymes and dissolved ions and nutrients.
What is the function of the cytoplasm?
Site of cellular reactions e.g. first stage of respiration.
Transport medium.
What is the function of the cell membrane?
Controls the entry and exit of materials into and out of the cell.
What is the function of the mitochondria?
Site of later stages of aerobic respiration in which ATP is produced.
Provides energy for the cell
What is the function of the ribosomes?
Joins amino acids in a specific order during translation for the synthesis of proteins.
What is the plant cell wall made of?
Cellulose
What is the function of the plant cell wall?
- Provides strength.
- Prevents the cell bursting when water enters by osmosis.
What does the permanent vacuole contain?
Cell sap (a solution of salts, sugars and organic acids).
What is the function of the permanent vacuole?
Supports the cell, maintaining its turgidity.
What is the function of chloroplasts?
Site of photosynthesis
Describe how sperm cells in animals are adapted to their function
- Haploid nucleus contains genetic information.
- Tail enables movement.
- Mitochondria provide energy for tail movement.
- Acrosome contains enzymes that digest the egg cell membrane.