Biology Exam 3

autocrine signaling

A type of localized signaling in which a cell secretes a signal molecule that affects itself is best described as

[Signal reception —> Signal transduction --> Cellular response]

Which of the following describes the entire process of signal transduction?

Second Messenger

A receptor activates adenylyl cyclase, which produces CAMP (cyclic AMP) - CAMP then goes on to activate another enzyme that ultimately causes the cellular response. This is an example of

[Receptor Tyrosine Kinase, RTK]

Upon activation by two ligands, this receptor will dimerize and autophosphorylate specific amino acids. The phosphorylated amino acids can then be used to activate several enzymes and activate multiple pathways. This receptor is a

[Apoptosis]

Due to overexposure to harmful UV rays from the sun, a skin cell receives DNA damage. The protein p53 (the guardian of the genome) binds to the damaged DNA to evaluate the damage, and decides the damage is too significant to repair. p53 then activates proteins such as caspaces that will activate to break down the cellular components. The cell eventually dies, its contents now in small packages called blebs that can be taken up by other cells. The process described is called

How do enzymes catalyze reactions?

By lowering the activation energy threshold

Why is P680 a strong oxidizing agent?

because it accepts an electron from oxygen since it has a greater affinity for them

Function of fermentation

recycle energy carrier

Laws of Thermodynamics

Energy cannot be created or destroyed and For a spontaneous process, the entropy of the universe increases

Anabolic pathways

builds up molecules

Catabolic pathways

breaks down molecules

Carbon Dioxide in cellular respiration

a waste byproduct of aerobic respiration in pyruvate oxidation and citric acid cycle

Where does glycolysis occur?

Cytosol

Where does pyruvate oxidation occur?

Mitochondrial matrix

Where does citric acid cycle occur?

Mitochondrial matrix

where does the electron transport chain occur?

Inner mitochondrial membrane

Where does chemiosmosis occur?

Inner mitochondrial membrane

How do enzymes work?

They speed up a reaction without being consumed by lowering activation energy, creating a template, stretching towards transition state, creating the right micro environment, or directly participating as an amino acid

Where does the linear electron flow take place?

Thylakoid membrane

Where does the cyclic electron flow take place?

Thylakoid membrane