Cell Structure and Functions Cell Structure and Functions Animal cells 1. Cell membrane 1. Cell structures membrane phospholipid bilayers and proteins functions: semi-permeable membranes, allow some molecules to go in or out, but do not allow others to go in or out. transport: active, passive and facilitated transport. endocytosis V.S. exocytosis 2. Cellular appendages cilia or flagella – for movement.

Animal Cell Structure

3. Mitochondria power house of the cells cellular respirations take place 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O + 38ATP double membrane, inner membrane fold to increase surface area. genetic material of its own. 4. Lysosome hydrolytic enzymes, e.g. lipase, proteinase, amylase etc. phagocytosis remove the injured cells molecules turn over

5. Ribosome large subunit (60S) and small unit (40S) rRNA and proteins for protein synthesis 6. Endoplasmic reticulum (E.R.) communication and transport system in the cell rough E.R. (with ribosome attached): protein synthesis smooth E.R. (no ribosome attached): lipid synthesis 7. Golgi complex packaging center combine different organic molecules for secretion

8. Centrioles a pair, perpendicular to each other regulate cell division 9. Nucleus double membrane structure the brain of the cells control all the activities in cells genetic materials in chromosomes nucleolus: a mass of RNA

Cell Cycle Cell Cycle Cell Cycle G 1 : Gap one, before DNA synthesis synthesis S : DNA synthesis G 2 : Gap two, after DNA synthesis synthesis M : prophase, metaphase, anaphase telophase anaphase telophase Cytokinesis : cytoplasmic division G1G1 S S G2G2 M

Animal Cell Mitosis Animation Reference:

Interphase Prophase Metaphase Anaphase Telophase

Onion Root Tips - Mitosis Reference:

Meiosis A special cell division, for the formation of sex cells. A special cell division, for the formation of sex cells. For the formation of egg – oogenesis. For the formation of egg – oogenesis. For the formation of sperm – spermatogenesis. For the formation of sperm – spermatogenesis. Resulting cells only have ½ no. of chromosomes and ½ amount of DNA Resulting cells only have ½ no. of chromosomes and ½ amount of DNA

Animal Cell Meiosis Animation Reference:

Comparison of Mitosis and Meiosis Animation Reference:

Differences between Mitosis and Meiosis MitosisMeiosis No. of cell division 12 No. of daughter cells 24 Amount of DNA samehalf Amount of chromosome samehalf Crossing over, synapsis