Lipoproteins and their functions: Chylomicrons, VLDL, LDL, and HDL

·   Chylomicrons- dietary triclycerols

·   VlDL- endogenous triglycerol, cholesterol ester cholesteroyl

·   LDL-delivers  cholesterol -->  extra hepatic tissues (bad cholesterol)

- Build cell membrane

·   HDL- carry cholesterol release from tissues -->  back to liver (good cholesterol cholesterol scavenger).

·   Chylomicrons

-   Deliever:

-  Exogenous fatty acids to muscle and adipose tissue

-  Dietary cholesterol to liver

-Other lipoprotein complexes: transport endogenous lipids in blood stream

-   VLDL     -->     IPL --> LDL (cholesterol Rich)

-  LDL -->  delivers cholesterol to extrahepatic tissues (“bad cholesterol”)

1.      Build cell membrane

2.      Synthesize steroid hormones

·         HDL- carry the cholesterol released form tissues back to the live (“good cholesterol”) (cholesterol scavenger)

What are “good cholesterol” and “bad cholesterol” and why?

-   Good Cholesterol -->  carry cholesterol from tissues (HDL)

- Bad Cholesterol --> LDL -->    delivers cholesterolà build cell membrane

Energy density

- Lipids are fuel with the highest energy density

how much energy→ lipids are the most energy dense

Definitions: Thermogenesis

·    Thermogenesis the process of heat production in organisms. It occurs mostly in warm blooded animals, but a few species of thermogenic plants exist.

·    In the brown fat tissue is through oxidation-phosphorylation uncoupling mechanism

Oxidation of Fatty acids: Where? Which two phases? Carnitine cycle

  Where --> mitochondria

  Two Phases

-Activation

-  transportation

Carnitine cycle-- can move across membrane of mitochondria--  transport--need Acetly before two things occur

Four reactions of oxidation: dehydrogenation (FAD), hydration, dehydrogenation

(NAD+) and thiolytic cleavage

  Dehydtogenation- remove hydrogen and make FADH2

  Hydration –add water

  Deydrogenation- make NADH

 Thioysis- make 5 ATP every cycle

Biosynthesis of fatty acids: Where, How and Coenzymes involved.

Where : in cytosol

How-

        Coenzyme- NADPH

The enzyme complex of fatty acid biosynthesis

Similarities and differences between the oxidation and fatty acid synthesis

(Locations, co-enzymes, enzyme complexes involved, fatty acyl carriers, reaction

directions, starting materials)

Which enzyme in the oxidation is associated with complex II of electron transport chain?

Basic composition of fatty acid synthase.

    Acetyl-CoA needs bind to start fatty acid synthase

    What enzymes make up fatty acid synthase

   Where --> cytosol

  Building-acetyle-coA (2 carbon)

Ketogenesis: location, function, ketone bodies, under what conditions

·Ketogenesisà the synthesis of ketone bodies from acetyl-CoA

Location: mitochondria of liver cells

Function: providing nutrition to brain when you don't have glucose

Ketone bodies--> 

8mM--> normal

20 mM--> toxic

Names- acetone, acetactate, B-hydroxybutrate

The key control enzyme in cholesterol biosynthesis

Building Block: Acetyl-CoA

The key control enzyme in Ketogenesis.

   HMG-CoA

What is a “Nitrogen Pool”

1.   Nitrogen pool -->

the sum total nitrogen compunds in the body, nonprotein anabolic produces

a-ketoglutarate – Glutamate” system

Glucose-Alanine Cycle and Glutamate-Glutamine system

   Two pathways to transport ammonia to the liver for urea synthesis

→Glucose→pytuvate→Alanine→pyruvate→Release NH2

Essential and nonessential amino acids

   Essential-must be provided by diet (end in-ine)

Nonessential-can be made by the body

Four common metabolic intermediates that link protein catabolism to carbohydrate

Pyruvate

Alpha-ketoglutarate

Oxaloacetate

  B-phosphglcerate

Essential and nonessential amino acids

   Essential-must be probided by diet (end in-ine)

Nonessential-can be made by the body

Four common metabolic intermediates that link protein catabolism to carbohydrate

Pyruvate

Alpha-ketoglutarate

Oxaliacetate

B-phosphglcerate

Excretion of excess nitrogen in liver from metabolic break down of amino acid

The transportation of ammonia to urea cycle

Glutamate – Glutamine System

                   Glucose – Alanine Cycle

All major intermediates in urea cycle

         Citrulline

        Arginosuccinate Acid

         Argenine

Orinthinthe

The final products of protein catabolism

Plasma→ water, proteins, elctrocytes:Na, K, Cl

    Serum--> A component of blood which is collected after coagulation

Transamination and oxidative damination

Transamintion-> important step in synthesis of non-essential amino acid

--reaction between an appha-keto acid

           -- Oxidate deamination--> generates            oxoacidsin liver

                      ---Glutamate undergoes rapid                                    oxidative deammation in Urea Cycle.                        -->prodces hydrogen peroxide and                            Ammonia

Plasma→ water, proteins, elctrocytes:Na, K, Cl

    Serum→ non protein portion →everything but protein

2.            Circulations: pulmonary, systemic and lymphatic circulations 

Pulmonary-Lungs

-RV →Lungs→ LV

-Accept O2 and Release CO2

Systemic circulation

-LV→tissues→RV

-Deliver O2 to tissues and pick up CO2 from tissues

Lymphatic Circulation

-Lymphatic, thymus, spleen and lymph nodes

-Lipid abosorption and distribution

-immunolgical function