Categories: All - signaling - receptors - photosynthesis - ions

by Adanna Onyeka 2 years ago

239

Concept Map 2

Cells communicate through various signaling mechanisms that involve different types of receptors. Membrane receptors, such as ion channel receptors, tyrosine kinase receptors, and G protein-coupled receptors (

Concept Map 2

Kinases are inactivated by protein phosphatases which remove a phosphate group

Citric acid cycle begins

Lactic Acid

Alcohol Fermentation

Anerobic respiration

transport protein - ATP Synthesis

concentration gradient

Chemiosmosis ATP Synthesis

Inner mitochondrial membrane

Electron Transport Chain

FADH2

H2O

Oxaloacetate

Malate

Fulmarate

Succinate

Succinyl CoA

a-ketoglutarate

Isocitrate

Citrate

Acetyl CoA

2 H+

2 NADH

2 ATP

2 H2O

2 Pyruvate

Water/H2O

Pyruvate

NADH

Net

Protons

Electrons

NAD+

Phosphate

ADP

ATP

Glucose

Energy Payoff Phase

Oxidative Phosphorylation

Pyruvate Oxidation

Energy Investment Phase

Glycolysis

Substrate level phosphorylation

Cellular Respiration

Cell Signaling

Releasing a signal

reception
transduction

response

Receptors
target cell that receives the signal molecule
Intracellular receptors:in cytoplasm & nuclues

steroid hormone aldosterone

Membrane receptors

includes

Ion channel receptor

when a signal molecule binds to the receptor, the gate allows a specific ion like sodium or calcium through the channel in the receptor

movement of ions through these channels may change the voltage across membranes

this would trigger action potential

Tyrosine kinase receptor

Polypeptide on dimerization functions as a kinase

it takes a phosphate group from ATP and adds it to another polypeptide

G protein linked receptor

signal molecule binds to the GPCR

slight alteration in the shape of GCPR allows for the G protein to bind to it

GDP is replaced with GTP on the G protein

G protein with GTP bound to it is active and it can now activate a nearby enzyme

all of the above steps occur in reception

Long distance signaling
Hormonal Signaling
Local signaling
Synaptic signaling
Paracrine signaling

Physical Contact

Plasmodesmata (plant cells)
Gap Junction (animal cells

Photosynthesis

C4-Cycle

Spatial separation of steps
CO2 enters the mesophyll cell through PEP carboxylase
Oxaloacetate(4C) is formed

malate(4C) is formed

Bundle Sheath cell

Pyruvate (3C)

PEP (3C)

CO2

calvin cycle

sugar

vascular tissue

CAM Cycle

Temporal separation of steps

Calvin Cycle

CO2 is introduced due to Rubisco
Phase 1 Carbon Fixation

as CO2 binds with rubisco it creates a short lived intermediate

after the short lived intermediate 3-Phosphoglycerate is made

with the introduction of 6 ATP and excretion of ADP 1,3-Bisphoglycerate is made.

with the introduction of 6 NADPH and the excretion of NADP+P we enter a new phase

Phase 2 Reduction

Glyceraldehyde-3-phosphate (G3P) is created by phase 1 and is the main sugar used by plants

Phase 3 Regeneration of the CO2 acceptor

3 ATP are introduced cause 3 ADP to leave

this creates Ribulose bisphosphate (RuBP)

NADP+P

Light Reaction

Photosystem II(P680)
light and water enter the complex

electrons from water are attached to the chlorophyll as protons and O2 are excecated out. light then causes the electrons to jump to an excited state

as the electrons jump to an excited state they are accepted by the primary acceptor

the electrons then go out a electron transport chain causing ATP to be released. the chain consist of plastoquinone (Pq), Cytochrome Complex, and Plastocyanin (Pc)

Photophosphorylation: ATP from ETC is used to pump H+ into thylakoid space. H+ diffuses down its concentration gradient through ATP synthase, forming more ATP.

Photosystem I(P700)

Cyclic Electron Flow-only used when the cell needs more ATP

Cytochrome Complex to the Plastocyanin creating ATP

plastocyanin then brings its energy to the chlorophyll

electrons get excited to the primary acceptor

electrons are then taken by Ferredoxin back to the Cytochrome Complex

as the electrons for the ETC enter the chlorophyll and more light exciting them they enter the primary acceptor

this causes another ETC consisting of ferredoxin (Fd) to NADP+ reductase.

NADP(+ )+ 2 H+ binds with NADP+ causing NADPH+H+ to be formed

Common relay molecule: Cyclic AMP

AMP after it activates the next step. Converted by phosphodiesterase (PDE).

ATP using the enzyme Adenylyl cyclase

Signal Transduction

Amplification of signals and coordination/regulation of cellular response

Response
Cellular response is activated after the transduction pathway is completed.

Expression of a gene

Transduction
Phosphorylation cascade

Activation of relay molecule (small, water-soluble molecule/ion), triggered by reception of ligand

Activation of a protein kinase 1

Activation of protein kinase 2 as protein kinase 1 transfers a phosphate group to it

Activation of an inactive protein as protein kinase 2 transfers a phosphate group to it

Activated protein triggers cellular response

Reception
Ligand (signaling molecule) binds to membrane receptor (e.g., GPCR)

GCPR adds GTP to G protein, which then activates membrane enzyme