BIO 181 Exam 2

Question 1

What are CDC2 kinase and cyclin, and how do they function to regulate cell cycle?

Answer 1

CDC2 kinase binds with cycline to become the Mitosis Promotion Factor (MPF)

Question 2

How does IP3 affect calcium ions in a cell?

Answer 2

IP3 causes the endoplasmic reticulum membrane to release calcium.

Question 3

What are the BRCA 1 and BRCA 2 genes?

Answer 3

They are the first genes to be broken at the start of breast cancer. People without these genes have a lesser chance of getting cancer.

Question 4

What are the similarities between photosynthesis and respiration?

Answer 4

They both use the Electron Transport Chain

Question 5

What is the relationship between the cell cycle and cancer?

Answer 5

The cell cycle works to regulate when cells divide. When you break the cycle, cancer develops.

Question 6

How have yeast shmoos helped us understand cell signaling?

Answer 6

Cell signaling factor is what causes yeast cells to grow towards each other for cell reproduction. Forms a shmoo.

Question 7

What are the steps of a cell signal inducing a response?

Answer 7

The receptors bind to recognition proteins and the protein activates a response.

Question 8

What are ATP, NADH, and NADPH?

Answer 8

They are all energy carrying molecules.

Question 9

What are G protein coupled receptors?

Answer 9

Uses Guanine Triphosphate. Signals the molecule with activates GTP. Uses GTP as a signal protein.

Question 10

What is apoptosis and why does it occur?

Answer 10

Plants- cell wall is present but everything inside is dead. Cell is signaled to start apoptosis.
Animal- cell has cancer, a virus, etc., it is told to go through apoptosis.

Question 11

What is a phosphorylation cascade?

Answer 11

Adding or subtracting a Phosphate group.

Question 12

What are the differences in cytokinesis in plant and animal cells?

Answer 12

Animals- contraction of the cell membrane to create a cleavage furrow
Plants- cell plate is formed to then become another cell wall.

Question 12

What is a scaffolding protein?

Answer 12

Holds other proteins in place in order for the reaction to occur more quickly.

Question 13

How do prokaryotes divide, and how does this compare to eukaryotic cell division?

Answer 13

Binary fission.

DNA is copied, duplicated, them pulled apart to create another cell.

Question 14

What are the first and second laws of thermodynamics?

Answer 14

I- energy in matter cannot be created nor destroyed

II- in every reaction you lose some energy, normally in the from of heat. (Entropy)

Question 15

How do cells communicate?

Answer 15

Direct communication
- gap junctions in animals, plasmodesmata is plants
Local signaling
Long distance signaling
- hormones travel through bloodstream to target cells

Question 16

How do anchorage dependency and density dependency inhibition regulate cell division?

Answer 16

Cells won’t multiply without being anchored to a substrate.
Cells won’t multiply after they have reached a certain density. (How the body regulates the right amounts of tissue being produced in the right places)

Question 17

What are growth factors?

Answer 17

Signals that induce mitosis. (MPF)

Question 18

What is activation energy, and how does it relate to the function of enzymes?

Answer 18

Enzyme- molecule serving as a catalyst, a chemical agent that increases the rate of the reaction.
Activation energy- the amount of energy that reactants must absorb in order for a chemical reaction to start.

Enzymes need activation energy to perform.

Question 19

What are metabolic, catabolic, and anabolic reactions?

Answer 19

Metabolism- Begins with a specific molecule which is then altered in a series of steps resulting in a product. (Eating food then breaking it down)
Catabolism- Breaking down molecules and releasing energy. (Cellular Respiration)
Anabolic- Building molecules consuming energy. (Anabolic Steroids)

Question 20

What is energy and what are the different types of energy?

Answer 20

Energy- The capacity to cause change.
Kinetic (Motion)
Thermal (Heat)
Potential (Stored)
Chemical (Potential energy for release in a chemical reaction)

Question 21

What are the major reactions of cellular respiration?

Answer 21

Organic compounds + Oxygen –> Carbon Dioxide + Water + Energy

C6H12O6 + 6 O2 –> 6 CO2 + 6 H2O + Energy [ATP + Heat]

Question 22

What are Glycolysis, Pyruvate Oxidation, The Krebs Cycle and the Electron Transport Chain, and Chemiosmosis?

Answer 22

Glycolysis- Breaks glucose into 2 molecules of Pyruvate. Makes ATP.
Pyruvate Oxidation- Pyruvate enters the mitochondrion and is oxidized to Acetyl CoA.
Krebs Cycle (Citric Acid Cycle)- Eight steps that completes the metabolic breakdown of glucose molecules after Pyruvate Oxidation occurs.
Electron Transport Chain- A sequence of electron carrier molecules that shuttle electrons down a series of reactions that release energy to make ATP.
Chemiosmosis- Uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work. It synthesizes the most ATP.

Glycolysis happens in the cytosol, outside of the mitochondria.
Pyruvate Oxidation, The Krebs Cycle, The Electron Transport Chain, and Chemiosmosis all happen within the Mitochondria.

Question 23

What is the interior structure of the mitochondria?

Answer 23

The matrix, cristae, and the intermembrane space.

The Krebs Cycle and Pyruvate Oxidation happens in the matrix, the Electron Transport Chain happens in the cristae.

Question 24

What are cristae, the intermembrane space, and the matrix?

Answer 24

Cristae-The folds of the inner membrane. Intermembrane space- The area in between the outer membrane and the inner membrane. Matrix- The area inside of the inner membrane.

Question 25

What are the major reactions of photosynthesis?

Answer 25

Light reactions and carbon fixation, dark reactions, light independent reactions, calvin cycle

Question 26

What are photosystems I and photosystems II and the Calvin cycle?

Answer 26

Starts in Photosystem II- Photon pushes an electron up to the primary acceptor. The electron travels down to make ATP. The electron enters Photosystem I, and another photon pushes the electron to primary acceptor, where it creates NADPH. Calvin Cycle- Metabolic pathway found in the stroma of the chloroplast in which carbon enters in the form of CO2 and leave in the form of sugar.

Question 27

What is photorespiration, and how do C4 and CAM photosynthesis help a plant avoid it?

Answer 27

Photorespiration- Peroxisomes and mitochondria rearrange and split the compound, releasing CO2. Consumes ATP, produces no sugar. CAM plants- Produce CO2 at night, and store it until the morning. Stomata closes to prevent photorespiration during the daytime. C4 plants- avoid stomata from opening and causing water loss.

Question 28

What is the interior structure of the chloroplast?

Answer 28

Thylakoids, grana, and stroma.

Question 29

What are thylakoids, grana, and stroma?

Answer 29

Thylakoids- Sacs suspended within the stroma which segregate the stroma from the thylakoid space inside these sacs. Grana- Thylakoid sacs that are stacked in columns. Stroma- A dense fluid that is surrounded by an envelope of two membranes in the chloroplast.

Question 30

What is the evolutionary origin of the reactions of photosynthesis and respiration?

Answer 30

Photosynthesis evolved first. Respiration evolved from photosynthesis.

Question 31

What are gap junctions and plasmodesmata?

Answer 31

A form of direct communication between cells. Gap junctions are found in animals, plasmodesmata is found in plants.

Question 32

What are tyrosine kinase receptors, ion channel receptors, and intracellular receptors?

Answer 32

Tyrosine Kinase Receptors- Catalyzes the transfer of a phosphate group from ATP to the amino acid tyrosine on a substrate protein. They are membrane receptors that attach phosphates to tyrosines. Ion Channel Receptors- Acts as a gate to restrict the flow of certain ions. Intracellular Receptors- Found in either the cytoplasm or nucleus. Receptors located inside the cell rather than on its cell membrane.

Question 33

What are mitosis and cytokinesis?

Answer 33

Mitosis- A process of nuclear division in eukaryotic cells. All cells except for sexual reproduction cells. Cytokinesis- The division of the cytoplasm to form two separate daughter cells. Cleavage furrow in animal cells, cell plate in plant cells.

Question 34

What are the major events of the cell cycle?

Answer 34

``` Interphase -G1 -S -G2 M Phase -Mitosis -Cytokinesis ```

Question 35

What events occur during Prophase, Metaphase, Anaphase and Telophase?

Answer 35

Prophase- Nuclear Envelope disappears, mitotic spindle forms. Chromosomes become visible. Metaphase- Chromosomes begin to align in the middle of the cell, microtubules attach to the chromosomes. Anaphase- Chromosomes travel up the microtubules to the opposite sides of the cell. Telophase- Opposite of Prophase. Nuclear envelope reappears, mitotic spindle disappears, and the cleavage furrow (in animals) and the cell plate (in plants) begin to form.

Question 36

How did mitosis evolve?

Answer 36

Bacteria --> Dinoflagellates --> Diatoms and Yeasts --> Most Eukaryotes