cell communication

Play an AI-generated podcast conversation about this lesson

What is the primary function of thylakoids in chloroplasts?

To convert chemical energy into ATP and NADPH
To store food energy in the form of starch
To synthesize glucose from carbon dioxide
To convert light energy into ATP and NADPH (correct)

What is the role of the excited reaction centre in photosynthesis?

To generate ATP and NADPH directly
To synthesize glucose from ATP and NADPH
To expel an electron, which passes down the electron transport chain (correct)
To absorb light energy and convert it into heat

What is the primary function of Rubisco in the Calvin-Benson cycle?

To synthesize chlorophyll from carbon dioxide
To catalyze the first major step of carbon fixation (correct)
To convert ATP and NADPH into glucose
To generate ATP and NADPH from light energy

What is the primary function of Phase 1 of the Calvin-Benson cycle?

To fix CO2 into a three-carbon molecule (D) Signup and view all the answers

What is the primary function of cell signalling?

To receive a signal, process it, and trigger a response (A) Signup and view all the answers

What type of cell signalling involves short-distance communication?

Paracrine signalling (D) Signup and view all the answers

What is the primary function of kinases in signal transduction?

To add phosphate groups to proteins (C) Signup and view all the answers

What is the role of cAMP in the signal transduction pathway involving adenylyl cyclase?

To activate protein kinase A (PKA) and stimulate glycogenesis (A) Signup and view all the answers

What is the effect of phosphorylation on protein activity?

It adds a negative charge to the protein and disrupts electrostatic interactions (B) Signup and view all the answers

What is the purpose of signal amplification in signal transduction pathways?

To amplify the signal in response to a stimulus (C) Signup and view all the answers

What is the role of phosphatases in signal transduction pathways?

To remove phosphate groups from proteins (C) Signup and view all the answers

What is the advantage of using second messengers in signal transduction pathways?

They are rapidly diffusible and can transfer the signal quickly (B) Signup and view all the answers

What is a characteristic of signalling molecules?

They can range from ions to proteins (D) Signup and view all the answers

How do most small molecules or ions cross the cell membrane?

With the assistance of specific protein carriers (C) Signup and view all the answers

What type of receptors interact with lipophilic ligands?

Intracellular receptors (B) Signup and view all the answers

What is the result of a conformational change in a receptor?

Reversible activation of the receptor (C) Signup and view all the answers

What is the function of an antagonist?

To bind to a receptor and block the action of an agonist (C) Signup and view all the answers

What is a characteristic of G-protein coupled receptors (GPCRs)?

They have seven transmembrane domains (B) Signup and view all the answers

What is the function of a G-protein in signal transduction?

To exchange GDP for GTP and activate downstream proteins (A) Signup and view all the answers

What is the result of the activation of a G-protein coupled receptor?

The G-protein dissociates into its components (D) Signup and view all the answers

What is the function of adenylyl cyclase in signal transduction?

To convert ATP to cAMP (C) Signup and view all the answers

What is the sequence of events in a signal transduction pathway?

Receptor activation, G-protein activation, protein kinase activation (D) Signup and view all the answers