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BCH 417 - Met Reg
Dr Schooly
42
Biology
Undergraduate 4
11/30/2009

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Term
Insulin
Definition
  • Two linked AA chains by disulfide bonds
  • Produced by Beta cells of the pancreas
  • Decreases Bool Sugar
Term
Glucagon
Definition
  • Produced by Alpha cells of pancreas
  • Increases Blood sugar
Term

Insulin Receptor (A)

Basic structure

Definition
  • Precuresor is a protien with a signal peptide that is cut off, protein is then cut into two parts, an alpha and a beta portion. Assembles into an alpha2beta2 dimer with 3 disulfide bonds
  • Beta portions are the transmembrane portion, contiains 3 key Tyr resisdues.
  • Alpha portions bind insulin.
Term

Insulin Receptor (B)

Reaction to insulin binding

Definition
  • The first insulin molecule binds to the first alpha portion which causes phosoralization of the 3 tyr portions of the Beta subunit. The second insulin binds causes the other try for the other beta unit to phosporalate.
  • The phosphoralation of the tyr residues causes tyr kinase activity. Which phosphorylates IRS-1, (insulin receptor substrate I)
  • IRS-1 -> Phosphoinositide-3-kinase -> PIP3 & others -> -> -> cAMP phosphodiesterase & Phosphoprotein phoshatate I
Term

Glucose Transporters

GLUT 1-7, 12

General overview

Definition
  • GLUT 1: Located in erythrocytes, kedney, colon, blood/brain barrier
  • GLUT 2: Liver, beta-cells of pancreas - low affinity for glucose, but high capacity
  • GLUT 3: Barin & neurons - high affinity for glucose
  • GLUT 4: muscles and adipocytes - the ONLY insulin senstive transporter
  • GLUT 5: Small intestine; fructose transporter, not glucose
  • GLUT 6: considered a psuedo gene
  • GLUT 7: Liver microsomes - connected with G6P and glucose export from the liver.
  • GLUT 12: unk function
Term

Glut 4

(Response to Insulin)

Definition
  • Found in muscle and fat cells
  • When the insulin signal is transmitted vesicals containing this will fuse adding this to the cell surface.
Term

GLUT 2

(More specific)

Definition
  • Found in liver and Beta cells of the pancreas
  • Special property is that it keeps the glucose levels inside these cells propotional to blood glucose levels.
Term
Body Response to Glucagon
Definition

elevates cAMP

decreasing glycolysis

increasing F(2,6)Bisphoshatase

decreases F(2,6)BP

increases gluconeogenesis

increcreases glyconeogenesis

increases TAG breakdown

increases ketone bodies

decreases blood pH

Term
Diabetes mellitus
Definition
  • Two Types
  • 1-0.5% US pop, insufficient production of insulin
  • 2  - Over 7% of US pop, bad or not enough receptors
Term

Isopernoid

(Are?)

Definition
  • Strutural components of membranes
  • Endocrine hormones, bile acids
  • vitamins A and D
  • part of vitaments E&K, chlorophyll, heme C, some neculeotides, perenylCys residues on proteins
  • terpenes
Term
Isoprenoids are used for
Definition

Structureal component of membranes

Energy Storage

Paracrine hormones (eicosanoids)

Term
What is the energetic cost of expoert of one AcCoA from the Mito?
Definition
1 ATP
Term
Thiolase
Definition
Converts 2 acetyl-CoA into acetoacetyl-CoA
Term
HMG-CoA synthase
Definition
Creates HMG-Coa from Acetyl-CoA and acetoacetyl-CoA
Term
Farnesol
Definition
Non-sterol derivative of mevalonate, know to inhibit HMG-CoA reductase which converts HMG-CoA into mevalonate.
Term
AsCoA
Definition
  • Has many biochemical functions, the one of interest for this lecture series is 2 AcCoA come together to from acetoacetyl-CoA (thiolase) then another adds on to form HMG-CoA (HMG-CoA synthase)
  • Costs 1 ATP to remove it from a mitocondria.
Term
Acetoacetyl
Definition
Formed by the addition of 2 AcCoA by thiolase, then used as an additive to another AcCoA to form HMG-CoA (HMG-CoA synthase)
Term
HMG-CoA
Definition
Formed from the addition of Ac-CoA and acetoacetyl-CoA, (HMG-CoA synthatse) and forms mevalonate with the use of 2 nadph (HMG-CoA dehrdogenase)
Term
Mevalonate
Definition
Formed by HMG-CoA dehydrogenase from, HMG-CoA dehdrogenase. First commited intermediate, in the liver it can only be used for ispoprenoid biosynthesis at this point. Converted next to mevalonate diphosphate (pyrophosphate) by mevalonate kinase, and phosphomevalonate kinase, consuming two ATP.
Term
Mevalonate Kinase
Definition
  • Convers Mevalonate to Phospomevalonate using 1 ATP.
  • Found in peroxisomes.
Term
Phosphomevalonate Kinase
Definition
  • Conversts phospomevalonate to mevalonate diphosphate using 1 ATP
  • Found in peroxisosmes
Term
Phosphomevalonate
Definition
Created by mevalonate kinase using 1 ATP, then convertered to mevalonate diphosphate by phosphomevalonte kinase.
Term
Mevalonae diphosphate decarboxylase
Definition
  • Converts Mevalonate diphosphate to IPP, CO2, isopentenyl diphosphate using one ATP->ADP
  • Found in peroxisomes
Term

Mevalonate diphosphate

(pyrophosphate)

Definition
Made from phospomevalonate by phosphomevalonate kinase as the cost of one ATP->ADP, it is then converted into IPP, CO2 at the cost of one ATP->ADP+Pi
Term
HMG-CoA reductase
Definition
  • Converts HMG-CoA to Melavonate in two steps utilizing 2NADPH
  • Contains 7 transmembraine domains
  • First commited step in isoprenoid synthesis
  • Lives in the walls of the ER
  • Activity decreased by phosphorylation.
  • Activity decreased by cholesterol and a non-sterol derivate of mevalonate, farnesol.
Term
IPP isomerase
Definition
  • Conversts IPP inot dimethylallyl diphosphate DMAPP
  • Found in peroxisomes
Term

Prenyl Transferase

(FPP synthase)

Definition
  • Condesation reaction of DMAPP and 2 IPP to make farnesyl PP (FPP).
Term
IPP
Definition
Created by mevalonate diphosphate decarboxylase, and isomerized to DMAPP by IPP isomerase.
Term
DMAPP
Definition
Formed from IPP by IPP isomerase and then two of them are joined by prenyl transferase (aka FPP synthase) to make farnesyl PP
Term

Farensyl PP

FPP

Definition
Formed by the combination of 2 IPP, and 1 DMAPP. Combines with another FPP to form squalene, this requires a reduction by NAPDPH.
Term
Squalene
Definition
Created by adding two FPP's together, this is then convereted to lanosterol, which has 3 carbons removed to make cholesterol.
Term
Lanosterol
Definition
Made from squalene converson, and is changed to cholesterol by removal of 3 carbons
Term
Ubiquinones
Definition
  • Made in mito
  • made using an alternative prenyl transferase
  • hook FPPs in trans double bonds together( 8-10, 40-50C)
  • Final step is the additon of p-OH-benzoic acid.
Term
Dilichols
Definition
  • Ancored in the ER membrane.
  • As diphospate esters they carry the sugars that are destined to be used as glycoprotein
  • synthized by cis polyprenyl diphospatesynthase, which elongates FPP.
  • The end is not cis nor trans, then two trans then all cis double bonds.
  • Largest non saponifiable lipids
Term
Prenylated proteins
Definition
  • Formed usually by cys, aliphatic amino acids x2, anything.
  • Big example gama G proteins.
Term
Bile Acids
Definition
  • We use about 20g a day, 500 mg/day are lost in feces
  • Created from cholesterol in a multistep process involving a number of cytochrome P450-mediated oxygenases.
  • iso-octyl side chain is removed as C3 leaving 5C acidic side chain. The double bond is lost and the A&B rings fuse.
Term
LDL transport
Definition
  • LDL is the most common way for cholesterol to travel in the blood. It consists of a protein called B-100 and is surrounded by phospholipids.
  • LDL receptor cause cells to take in the LDL bubble
Term
familial hypercholesterolemia
Definition

Caused by a lack of LDL recptorns

Have really really high cholesterol levels.

Term
isopentenyl adenine
Definition
Modified nucleoside found in tRNA
Term
Isoprenoids - plants and bugs
Definition

terpenes

sesquiterpenes

juvenile hormone

caretanoids

 

Term
Amino Acid metabolism, basic facts
Definition
  • ingest on average 100 g a day
  • 400 g used for metabolism, 10-15% of our dayly enegry supply
  • All proteins is absorbed, not excreted, and what is not used to build muscle is turned over into energy
  • Esential Amino Acids - His, Lys, (2/3 basic aa) Ile, Leu, Val,(branch chain) Phe, Try (aromatic)
  • Rest considered Non-essential
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