BIOS 100 EXAM 2
• Krebs Cycle: 1. Pyruvate converted to acetyl CoA, releasing CO2
2. Acetyl CoA enters the cycle
3. 2CO2, 3NADH, and 1 ATP made from each cycle
• Oxidative Phosphorilation: 1. e- are passed from NADH to electron transportchain (ETC)
2. H+ gradients are produced
3. Drives ATP synthase (ADP--> ATP)
4. O2 accepts electrons, producing water
• Citric Acid Cycle: Produces 2ATP
• LECTURE#9
Cell division: LECTURE#9Cell division
• Why do cells divide?: 1. Renewal and repair of tissues
a) stem cells are capable of self renewal
b)give rise to descendant cells
2. Asexual and Sexual Reproduction
a) Prokaryotes divide through binary fission as a response to their environment
b) Eukaryote cell division is more complex
• Bacteria reproduce...: Asexually
• Life cycle of a cell: 1. Series of events in the life of a cell
2. Time to complete the cell cycle
a) dependent on organism, cell type, and life stage
3. Consists of 2 main stages:
a) interphase (most cells spend 90% of lifespan in this stage)
b) Cell division (mitosis and cytokinesis)
• G-O: Resting phase of the cell
• G-1: Make proteins for cell division
• S-phase: Replicates DNA
• G-2: checks conditions
• Mitosis and cytokinesis: Cells divide fully
• Interphase: 1. Longest phase of the cell
, 2. Period between division
3. Cell preps to divide
4. 3 Stages:
a) G1: growth after mitosis
b) S: DNA synthesis
c) G2: growth before mitosis
• G1 and G2 phases: G="gap"
1. Early biologists saw a gap between S phase and cell division
2. Periods of growth (cell size. and protein content increase)
3. Prep of next phase
4. checkpoint ensuring conditions are suitable
• G0 phase: 1. Most cells not actively dividing
2. Can last days to years
3. Some cells will divide again and again (liver cells)
4. Some cells stay in this phase (nerve cells)
5. DNA packaged in chromosomes
6. DNA molecules are long (2m)
7. DNA tightly packed with proteins
8. Chromatin: DNA and proteins
• Plasma membrane: The "gatekeeper" of the cell
1. all cells have one
2. membranes are semi-permiable
3. separates the cell from its environment
4. biologically important molecules are transported cross the membrane
5. hydrophobic phospholipid bilayer
6. Large molecules and charged molecules cannot pass through, but small mole-cules, and
hydrophobic molecules can
3. Concentration of Gradients: Areas of abundance to scarcity
4. Passive transport: 1. "easier" Downhill energy
• Krebs Cycle: 1. Pyruvate converted to acetyl CoA, releasing CO2
2. Acetyl CoA enters the cycle
3. 2CO2, 3NADH, and 1 ATP made from each cycle
• Oxidative Phosphorilation: 1. e- are passed from NADH to electron transportchain (ETC)
2. H+ gradients are produced
3. Drives ATP synthase (ADP--> ATP)
4. O2 accepts electrons, producing water
• Citric Acid Cycle: Produces 2ATP
• LECTURE#9
Cell division: LECTURE#9Cell division
• Why do cells divide?: 1. Renewal and repair of tissues
a) stem cells are capable of self renewal
b)give rise to descendant cells
2. Asexual and Sexual Reproduction
a) Prokaryotes divide through binary fission as a response to their environment
b) Eukaryote cell division is more complex
• Bacteria reproduce...: Asexually
• Life cycle of a cell: 1. Series of events in the life of a cell
2. Time to complete the cell cycle
a) dependent on organism, cell type, and life stage
3. Consists of 2 main stages:
a) interphase (most cells spend 90% of lifespan in this stage)
b) Cell division (mitosis and cytokinesis)
• G-O: Resting phase of the cell
• G-1: Make proteins for cell division
• S-phase: Replicates DNA
• G-2: checks conditions
• Mitosis and cytokinesis: Cells divide fully
• Interphase: 1. Longest phase of the cell
, 2. Period between division
3. Cell preps to divide
4. 3 Stages:
a) G1: growth after mitosis
b) S: DNA synthesis
c) G2: growth before mitosis
• G1 and G2 phases: G="gap"
1. Early biologists saw a gap between S phase and cell division
2. Periods of growth (cell size. and protein content increase)
3. Prep of next phase
4. checkpoint ensuring conditions are suitable
• G0 phase: 1. Most cells not actively dividing
2. Can last days to years
3. Some cells will divide again and again (liver cells)
4. Some cells stay in this phase (nerve cells)
5. DNA packaged in chromosomes
6. DNA molecules are long (2m)
7. DNA tightly packed with proteins
8. Chromatin: DNA and proteins
• Plasma membrane: The "gatekeeper" of the cell
1. all cells have one
2. membranes are semi-permiable
3. separates the cell from its environment
4. biologically important molecules are transported cross the membrane
5. hydrophobic phospholipid bilayer
6. Large molecules and charged molecules cannot pass through, but small mole-cules, and
hydrophobic molecules can
3. Concentration of Gradients: Areas of abundance to scarcity
4. Passive transport: 1. "easier" Downhill energy
