Photosynthesis & Cell communication (ch10&11)

Question 1

what are the light reactions of photosynthesis

Answer 1

• occurs in the thylakoid membranes
• converts solar energy to chemical energy
• transfers electrons & protons from water to NADP+, forming NADPH
• produces ATP from ADP through phosphorylation

Question 1

properties of light

Answer 1

light is a form of electromagnetic energy
light has wavelike properties

Question 2

purpose and products of the calvin cycle

Answer 2

uses ATP & NADPH produced during light reactions to generate G3P

Question 3

quorum sensing

Answer 3

method of cell communication that allows bacteria to detect population density

Question 4

local signalling

Answer 4

occurs between nearby cells
- direct contact via cell junctions & cell-cell recognition
- paracrine/synaptic signalling

Question 5

long-distance signalling

Answer 5

communication throughout an organism
- based on secretion & detection of signalling molecules produced by plants & animals

Question 6

what occurs in the reception stage of cell signalling

Answer 6

a cell detects a signalling molecule outside of the cell
- requires a receptor protein to recognize signalling molecules
- signalling molecule acts as ligands (binding impacts shape & function of receptor)

Question 7

what occurs in transduction stage of cell signalling

Answer 7

series of steps (cascades) that converts a signal (with second messengers) to cause a specific cellular response
- multistep signal transduction pathway involving relay molecules

Question 8

what occurs in the response stage of cell signalling

Answer 8

transduced signal finally triggers a specific cellular response, involving catalysts, activation of genes, etc.

Question 9

what are receptor proteins

Answer 9

bind to signal molecules, and the resulting structural change temporarily modifies the function of the receptor

Question 10

G protein-coupled receptors (GPCRs)

Answer 10

work with a G protein that binds GDP/GTP

Question 11

Receptor tyrosine kinases (RTKs)

Answer 11

self-phosphorylates, dimerizes, & structurally modifies relay proteins

Question 12

Ligand-gated ion channel receptors

Answer 12

a channel that opens in response to signal molecule binding

Question 13

secondary messengers

Answer 13

small, nonprotein molecules involved in signal transduction

Question 14

types of responses elicited by signal transduction pathways

Answer 14

• changes in gene expression via transcriptional regulation
• changes in rate of protein’s activity (cell function)

Question 15

signal specificity

Answer 15

different cells have different responses to the same signal based on their collection of proteins (proteome)

Question 16

signal termination

Answer 16

cellular response to a signal needs to stop once the signal is removed