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Cell Processes Review. Part 2. Cell Cycle. The cell cycle is an ordered set of events, culminating in cell growth and division into two daughter cells. Mitosis. Growth occurs in the G1 and G2 phases. The S stage stands for "Synthesis". This is the stage when DNA replication occurs.
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Cell Processes Review Part 2
Cell Cycle • The cell cycle is an ordered set of events, culminating in cell growth and division into two daughter cells.
Mitosis • Growth occurs in the G1 and G2 phases. • The S stage stands for "Synthesis". This is the stage when DNA replication occurs. • The M stage stands for "mitosis”. In mitosis, two genetically identical daughter cells are produced.
Meiosis • Meiosis is the process by which a cell divides and produces sperm or egg cells. • This process happens only in the reproductive cells. • In this process the cell must divide in half twice. When a cell divides during meiosis, four new cells are created. As each sperm or egg is made, new combinations of chromosomes and genes are created.
Mitosis vs. Meiosis • Purpose: • Mitosis: To make daughter cells identical to the parent cells - eg during growth and repair. • Meiosis: To produce sex cells (gametes). • Takes place: • Mitosis: In all cells apart from gametes. • Meiosis: In the reproductive organs (ovaries and testes).
Mitosis vs. Meiosis • Produces how many cells? • Mitosis: Two daughter cells. • Meiosis: Four gametes. • What happens to number of chromosomes? • Mitosis: Same number as in parent cell. • Meiosis: Half as many as in parent cell (The original number of chromosomes is restored when two gametes fuse to form a zygote.)
ATP • Molecule that stores and releases energy in the bonding of the end phosphate molecule.
Cellular Respiration • Process in which energy (ATP) is produced from food (glucose). • 3 steps: glycolysis, citric acid cycle, electron transport chain C6H12O6 + 6O2—> 6CO2 + 6H2O
Glycolysis • 6-carbon glucose molecule is broken down to two 3-carbon molecules. • Oxygen is NOT required. • 2 net ATP molecules are produced.
Citric Acid Cycle • aka Kreb’s Cycle • 3-carbon molecules are broken down in CO2 • 2 net ATPs are produced • high energy electrons are sent to electron transport system CO2 high energy electrons
Electron Transport Chain • Electrons go through several chemical reactions to produce a net of 34 ATPs.