_6093 Bio Syllabus Notes

Requirement I: Cells and Chemistry of Life Structure and function of: Cell Wall Cell Membrane Cytoplasm Nucleus Vacuole Chloroplasts Cell wall (Made up of cellulose and FULLY permeable) - Gives plant cells a fixed shape - Provides structural support and protection Cell Membrane (Made up of lipids and proteins) - PARTIALLY permeable - Control movement of substance in and out of cell Cytoplasm (Jelly like fluid containing water, salt, and protein) - Contains organelles that perform specific jobs within a cell for a particular function Nucleus (Surrounded by nuclear membrane) - Controls cell activities like cell growth and repair of worn out parts - Essential for cell division as chromosomes contains DNA that has genetic information and instructions for cell activities Vacuole -> Store substances within the cell Plant -> Large and central, Contains cell sap (dissolved sugars, mineral salts, and amino acids) Animal -> Small and temporary, Contains water and food substances

Chloroplast - Contains chlorophyll which is essential for photosynthesis Structure and function of: Ribosomes Golgi Body RER SER Ribosomes (Made of rRNA proteins) Attached to RER -> Synthesises protein that’s transported out of cell Lies freely -> Synthesis proteins that are used within the cel RER (Continuous with nuclear membrane) - Modifies & packages protein made by ribosomes into vesicles to the Golgi Body for secretion out of the cell Golgi Body 1) Chemically modifies substances made by ER 2) Stores and packages substances in vesicles for secretion out of the cell SER (More tubular) 1) Synthesis of fats and steroids (sex hormones in mammals) 2) Detoxification Compare structure of animal and plant cell Large central vacuole vs Small temporary vacuole Chloroplast vs no chloroplast Cell wall vs no cell wall

How are red blood cells adapted to their functions? 1) Contains many haemoglobin -> Transports O 2 by temporarily binding to it to form oxyhaemoglobin 2) No nucleus -> More haemoglobin -> ↑↑ O 2 - carrying capacity 3) Biconcave shape -> ↑↑ SA-V Ratio -> ↑↑ O 2 and CO 2 diffusion in and out of cell 4) Flexible -> Turns bell-shaped to pass through narrow capillaries -> Ensures O 2 can be delivered to every tissue in the body How are muscle cells adapted to their functions? 1) Many mitochondria -> ↑↑ rate of aerobic respiration -> Release large amounts of energy for contraction of muscle cells 2) Many nuclei -> ↑↑ protein synthesis 3) Stores glycogen -> Converted to glucose for immediate en