Bio Exam 3

Enzymes

100

Name at least 2 factors that effect enzymes?

Enzyme/substrate concentration

temperature

pH

inactive forms

Inhibitors

Irreversibe

compartmentalization

200

Define the following terms:

- kinase

- phosphatase

- phosphorylation

- dephosphorylation

- kinase: type of enzyme that adds phosphate

- phosphatase: type of enzyme that removes phosphate 

- phosphorylation: process of adding a phosphate 

- dephosphorylation: process of removing a phosphate

300

Define the different types of cell signaling

Local signaling:

Paracrine: Acts on cells near by by secreting molecules of a local regulator

Synaptic:Nerve cell releases neurotransmitter into synapse, which stimulates target cell like a muscle or nerve cell

Long distance:

Endocrine: Hormones. Endocrine cells secrete hormones into body fluids, like blood. Reach most body cells but only bind to/affect some cells 

400

Describe the difference between competitive and non-competitive inhibitors. Describe how Allosteric regulation works. 

Competitive: inhibitor will bind to active site

non-competitive: inhibitor binds to another site

Allosteric regulation: type of non-competitive. can either activate or inactivate and enzyme by binding to the allosteric site. results in a shape change in the enzyme. 

500

The body uses cAMP, cyclic adenosine monophosphate, as a secondary messenger in essential cellular pathways in order for the body to produce specific hormones and neurotransmitters. During a metabolic pathway, cAMP will bind to PKA to activate it, and in turn, the PKA will phosphorylate other proteins. This allows the appropriate cascade to occur and results in cellular responses. What type of enzyme is PKA? 

kinase

CAC/Oxidative phosphorylation

100

List the locations of pyruvate oxidation, CAC, and ETC/ATP synthase

Pyruvate oxidation: matrix

CAC: matrix

ETC/ATP synthase: Along Inner membrane

200

If 5 glucose molecules enter glycolysis, how many acetyl-coA’s would enter the citric acid cycle? What would be your total end products of the citric acid cycle? 

10 Acetyl-Coa

End products of CAC:

30 NADH,10 FADH2,10 ATP, 20 CO2

300

What happens to the CO2 that is produced during cellular respiration? Since O2 is required for much of the processes in cellular respiration, how does it enter the cell?

CO2 diffuses out and O2 diffuses in

400

If 2 glucose molecules enter cellular respiration, what would be the total amount of NADH and FADH2 that will enter oxidative phosphorylation?

20 NADH

4 FADH2

500

Explain the concept of oxidative phosphorlyation

NADH and FADH2 will “drop off” electrons, which will go through the different protein complexes. This will allow for a proton gradient to form across the membrane. These protons will re-enter the matrix of the mitochondria by passing through ATP synthase, which will release energy since it is going from a high concentration to a low concentration. This energy allows for ATP to be generated.

Glycolysis/Fermentation

100

True or false: Glycolysis requires oxygen to be present in order to function

Flase

200

During fermentation, what is the key molecule that is being reproduced for glycolysis to run? 

NAD+

300

Where does Glycolysis occur in the cell/how does glucose enter the cell?

Glucose enters through a glucose permease carrier protein, and glycolysis occurs in the cytosol of the cell. 

400

Why is there an energy investment phase and a energy pay off phase in glycolysis? 

You have to use 2 ATP at the beginning of the cycle to break down glucose. You then are able to make 4 ATP during the energy pay off phase. 

500

If 8 glucose molecules entered cellular respiration, what would be the total end products of glycolysis?

 

Net 16 ATP

16 NADH

16 Pyruvates

Photosythesis

100

What are the two different pathways in Photosynthesis called?

Light-dependent reactions and light-independent reactions. 

200

What specific molecule does chlorophyll have at its center? Also, how does chlorophyll a and chlorophyll b differ? 

- contains Mg

- Chlorophyll a has a CH3 group

- Chlorophyll b has a CHO group 

300

Where is ATP and NADPH produced in photosynthesis? Where do the light-dependent reactions and light-independent reactions occur? 

ATP/NADPH: stroma

light-dependent rxn: along thylakoid membrane

light-independent rxn: stroma 

400

Draw the Calvin cycle. Should include key products produced per one cycle, the key enzyme that is used at the start of the cycle, and the key 5 carbon molecule that is reproduced at the end of the cycle. 

500

Draw the basic diagram of photosystem II and I that shows how the light is used, e- flow, use of the electron transport chain. List the main products of this process and where they go to next. 

See SI leader

Main products: NADPH and ATP to be used in the calvin cycle. 

Random

100

How is water used in photosynthesis? What does it produce as a waste product?

Used to replace low-energy electrons

Produces O2 as a waste product

200

NADH  + H+  → NAD+ + H+

FAD+ + H+  → FADH2  + H+
Label which is being oxidize and which is being reduced

Oxidized: NADH

Reduced: FADH2

300

Explain the difference between C4 and CAM pathways

C4: are in environments that have low CO2. Will employ a spatial separation of capturing CO2 and using CO2 (Calvin cycle). 

CAM: are in environments that have extreme temperatures. Will close their stomata during the day to save water( will perform the Calvin cycle at this time), and open them at night to capture the CO2. 

400

Explain the two forms of Irreversible Enzyme inhibition

- cell will not do itself

Substrate mimic: a molecule that mimic the substrate will get stuck in the active site covalently.

Denaturation of enzyme: can be from multiple different factors, overall it results in the disruption of the bonds within the enzyme. 

500

Draw a cell and, using arrows, show the process of cellular respiration