Cell biology

Properties of EUKARYOTIC cells.

Animal cells, have cell membrane, cytoplasm, and DNA enclosed in a nucleus.

Properties of PROKARYOTIC cells.

Bacterial cells, Single cell organisms, cell membrane and cytoplasm surrounded by cell wall. DNA left loose in loops/ small rings called plasmids.

What is the equation of magnification?

Image size / actual size = magnification

What is the difference between light and electron microscope?

Electron microscope = much higher resolution, can only study dead cells.

Light microscope = lower resolution, can examine living cells.

Nucleus function:

Acts as a control center and coordinates growth, while also containing the cells DNA.

Cytoplasm function:

Jelly like substance supporting organelles and a site of metabolic activities.

Cell membrane function:

Acts as a cells barrier and boundary, controlling movement of substances in and out of cell.

Mitochondria function:

Produces energy through respiration.

Ribosomes function:

Site of protein synthesis.

Cell wall function:

Strength and structural support - It provides rigidity and protects the cell and its contents.

Chloroplasts function:

Contains chlorophyll and primary site of photosynthesis.

Vacuole function:

Storage of minerals and other substances.

How are microorganisms cultured?

Cultured in a medium including many nutrients petri dishes with agar gel

Explain mitosis.

The cell grows to increase number of sub-cellular structures.

Genetic material is replicated to form two copies.

The chromosomes are then pulled to opposite ends of the cell and the nucleus splits.

The cytoplasm and cell membranes divide to form two identical daughter cells.

Stem cells

Undifferentiated cells found in bone marrow (which can only specialise into blood cells) and in embryos (specialise into most cells)

Diffusion.

The process of molecules travelling from and area of high concentration to low concentration. Does not require energy. Increased rate with increased temp and surface area.

Osmosis:

The process of water molecules travelling from and area of high concentration to low concentration through a partially permeable membrane. Does not require energy.

Active Transport:

The process of molecules travelling from and area of low concentration to high concentration. Does require energy.