BOTAONE long exam 2 reviewer

what happens to the nucleus in preparation for cell division?

the nucleus is not always in the enter but for it to divide properly, it has to be in a proper position where it can divide its contents more efficiently and accurately so it will move towards the center

what is the preprophase band?

it determines the orientation of the division plane

what is the phragmosome?

a layer of cytoplasm that forms in the plane where cell division will occur

what is DNA composed of?

nucleotides

what are the phases in interphase?

- G1 phase
- G0 phase
- S phase
- G2 phase

what happens in the G phase?

gap for growth

what happens in G1?

- G refers to the gap between cell division and DNA synthesis
- gathers materials and prepares organelles (the cell makes more of ER, ribosomes, and cytosol to make 2 functional cells)

what happens in the S phase?

- DNA is duplicated

what happens in the G0 phase?

some cells will stop dividing and can either move on to specialization or die

explain the process that happens in duplication of DNA in the S phase

1. each nucleotide has a phosphate sugar and a base connected to it
2. there is an enzyme that will cause one end to unzip from top to bottom
2. once it starts to unzip, there ill be nucleotides somewhere which will start to connect with each other in a sequence that will complement this strand
3. as they separate, their complementary strands are also beginning to assemble
4. there are now 2 DNAs which are bound together to form 1 chromosome

what happens in the G2 phase?

- this phase spans the time from the completion of DNA synthesis to the onset of cell division
- the cell grows in size because the contents of the cell are increasing

what happens in the M phase?

4 stages: prophase, metaphase, anaphase, telophase

what happens in prophase?

- chromosomes in the nucleus appear as sister chromatids
- nuclear envelope disintegrates
- nucleolus disappears
- mitotic spindle begins to form between centrioles
- kinetochores begin to mature and attach to spindle

what happens in metaphase?

- chromosomes start to align in the middle
- even if the nuclear membrane disappears, the chromosomes are still in the middle of the cell and they start to line up before they can be equally divided

what happens in anaphase?

- sister chromatids will split into 2 single chromosomes (each with 1 chromatid) where they migrate to opposite poles; 2 daughter cells

what happens in telophase?

- chromosomes are gathered at opposite poles
- the clustering of the chromosomes at the opposite poles will trigger the materials to re-assemble together
- nuclear membrane starts to form and start to encircle each set of chromosomes

what happens in cytokinesis?

- the cell wall materials will assemble together and will form as a vesicle
- those vesicles join together to form the cell plate
- become longer and join with the old cell wall of the original cell, separating the 2 daughter cells

what is the function of cell cycle control?

makes sure there are no "rejects" in the process

what is the function of checkpoint proteins in cell cycle control?

they monitor progression throughout the cell cycle

what are the four checkpoints and in what stages are they found?

- Restriction checkpoint (G0)
- DNA damage checkpoint (during G1 and G2)
- Apoptosis checkpoint (right after G2)
- spindle assembly checkpoint (anaphase)

what is polyploidy?

process of genome doubling that gives rise to organisms with multiple sets of chromosomes

in what organisms does polyploidy usually occur?

happens mostly in plants which are domesticated (have been removed from the wild, planted in some place, and domesticated over and over in different places)

does polyploidy happen in mitosis or meiosis?

meiosis

when does cellular respiration occur?

after photosynthesis

why is cellular respiration not a cycle?

because its products are not exactly the inputs of photosynthesis

where does cellular respiration occur in the cell?

- glycolysis and Kreb's cycle: cytoplasm
- pyruvate oxidation: mitochondria
- Kreb's cycle: mitochondria
- ETC and oxidative phosphorylation: mitochondria

what is the chemical formula for cellular respiration?

C6H1206 + 6O2 -> 6CO2 + 6H2O + ATP

after cellular respiration, what happens to the H atom in the form of water (cellular respiration formula)?

the H in the form of water now just has a simple electron attached to it; the energy it used to carry is now in ATP

what are the 4 stages of cellular respiration?

1. glycolysis
2. formation of acetyl CoA
3. Kreb's/Citric acid cycle
4. ETC

what are the steps in the energy investment phase of glycolysis?

1. 2 ATP is broken down into ADP; removal of ATP bonds results in energy release and is inputted in the glycolysis process2 ATP is used
2. From a 6 carbon molecule, glucose is split into two 3 carbon molecules

what are the steps in the energy yielding phase of glycolysis?

1. 4 ATP is produced by substrate-level phosphorylation
2. 2 NAD+ takes the H atom from the two 3 carbon molecules and becomes 2 NADH (the H atom carries the energy from the sun)
3. A little energy was removed and was built in ATP
4. Energy decreases further up to the point where you are left with 2 molecules of pyruvate (for every molecule of glucose) with a little less energy compared to the original
5. 2 pyruvate has to be further processed to remove the energy built in the molecule

what is the total amount of energy produced in glycolysis?

- 4 ATP formed - 2 ATP used → 2 ATP
2- NAD+ → 2 NADH + H+
- total: 2 + (3 x 2) = 8

what are the steps in the formation of Acetyl CoA?

1. 2 pyruvate will enter the mitochondrion through active transport (2 ATP is used)
2. The oxidation of pyruvate's carboxyl group gives off CO2
3. In 2 pyruvate, the carbon molecules are removed one by one (oxidation)
4. With the removal of 1 carbon, the H atoms are picked up by NAD+, forming NADH (the H captured carries energy from the sun)
5. the 2 carbon pyruvate becomes Acetyl CoA (2 acetyl groups); the 2 acetyl groups lost energy but is now in NADH