Cell Bio Midterm 2

How is NADPH which received electrons from the photosystem I exported to the cytosol?

None of the above

Glucose transport across the membrane can be coupled with the transport of which ion?

Na+

What type of ion channel is channelrhodopsin?

Light-gated

Which of these molecules inhibits apoptosis?

Bcl2

In the synapse, the axon terminal always belongs to ____.

Presynaptic neuron

"Treadmilling" in cytoskeleton dynamics refers to:

The process of polymerization and depolymerization of cytoskeletal filaments at opposite ends at the same rate

The reaction with a ____DeltaG needs to be coupled to the reaction with a ____DeltaG.

Positive, negative

Which enzymes dephosphorylate their substrates?

Phosphatases

Which of these molecules is in its oxidized form?

FAD

Oxidation is the ____ of electrons and it causes the number of C-H bonds to ____.

Loss, decrease

Which protein causes microtubule bending in a Eukaryotic flagellum?

Dynein

To which complex does mitochondrial NADH deliver its electrons?

Complex I

What are the three main transition points during the cell cycle?

Midway M, Late G1, G2/M

In which cellular compartment is pyruvate synthesized during glucose catabolism?

Cytosol

Which of the following statements accurately describes the difference between the G0 phase and terminal differentiation?

G0 phase is a reversible state, whereas terminal differentiation is an irreversible process.

Which stage of oxidative phosphorylation uses proton gradient?

ATP synthesis

Which mobile carrier transports electrons from Complex I to Complex III?

Ubiquinone

During ATP synthesis, H+ ions move from ____ to ____ through ATP synthase.

Mitochondrial intermembrane space, mitochondrial matrix

After O2, which of these components of the electron transport chain has the highest redox potential?

Cytochrome c oxidase complex (IV)

What is the primary function of desmosomes?

Joining intermediate filaments between two adjacent cells

What is the term for a stack of thylakoid discs?

Granum

During which metabolic process is ATP used?

Carbon fixation reactions

ATP synthase uses the H+ gradient created by:

Photosystem II and Electron Transport Chain

Which carbohydrate is released from the Calvin cycle?

Glyceraldehyde 3-phosphate (G3P)

Which protein typically moves toward the plus end of the microtubule?

Kinesin

A membrane potential is the difference in electrical charge between:

The inside and outside of the cell

Skeletal muscles contract in response to calcium release from the sarcoplasmic reticulum. What component is responsive to calcium during this process?

Troponin complex

Which of the following best describes a chemical reaction with a negative DeltaG?

The reaction proceeds spontaneously and releases free energy

During which stage(s) of glucose catabolism is CO2 produced?

Link reaction

Which protein inactivates M-Cdk?

Wee1 kinase

DNA helicase binds to DNA during the ____ phase of the cell cycle and gets activated during the ____ phase.

G1, S

Where does the ATP molecule store its high energy?

Phosphate bond

You isolated a mysterious eukaryotic microorganism capable of performing fermentation. You detected a CO2 release during this process. Assuming that this organism uses one of the conventional fermentation pathways, what is the final organic byproduct of glucose catabolism in anaerobic conditions?

Ethanol

What is the role of caspase in cellular physiology?

Caspases initiate and execute programmed cell death

What brings the membrane back to its resting potential after depolarization?

K+ channels allow K+ to exit the cell

Which ion has a higher concentration in the cytosol compared to the extracellular environment?

K+

A neuron fires when:

Depolarization exceeds the threshold for excitation

What type of mutations in proto-oncogenes can contribute to the development of tumors?

Mutations in the coding sequence that result in hyperactivation of proto-oncogenes

Which transport mechanism reestablishes the ion gradient in neuronal cells, after return to resting potential after depolarization?

Na+/K+ pumps

Which organelle contains thylakoids?

Chloroplast