Descrbe the process of the mobilization of fatty acids

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1. Hormone binds to the receptor on adipocyte (fat cell)

2. The receptor signals for the activation of PKA

3. PKA phosporylates lipase and...

4. Phosphorylates Perilipin, allowing lipase to access lipid

5. Hydrolysis releases fatty acids from glycerol (triacylglycerol)

6. The fatty acids enter the bloodstream and attach to an albumin

7. Fatty acid transporter takes up fatty acid into myocyte (muscle cell)

8. Fatty acid is oxidized

Fatty acyl-CoA (acyl-CoA transferase I)

Fatty acyl carnitine (carnitine acyltransferase)

Fatty acyl carnitine

1. β-ozidation produces Acetyl-CoA

2. Acetyl-CoA is oxidized in the citric acid cycle

3. NADH and FADH2 donate e- to mitochondrial respiratory chain ultimately yielding ATP

True or False;

β oxidation only works on even numbered carbon chains?

True or False;

β oxidation only works on cis double bonds

True or False;

β oxidation cannot work on 2 double bonds

True or False;

Malonyl-CoA is found in fatty acid degredation?

What is biotin carboxylase?

In the fatty acid biosynthesis cycle, what is the repeating four step sequence?

1. Condensation of malonyl CoA with fatty acids

2. Keto reduction

3 Dehydration

4. enoyl reduction

 Vertabrate fatty acid synthase has a single polypeptide chain - bilobed dimer

Fungal fatty acid synthase has 2 seperate chains - double ring

What is this a picture of?

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KS transfers butyryl group from ACP to itself

MAT transfers new malonyl group to ACP

KS condenses malonyl group with butyryl group

1st acetyl group ends up furthest from the carboxylate

substrate is physically linked to FAS through the whole process

Palmitic acid is released from FAS by cleavage by thioesterase

True or False;

For the production of DELTA 9 unsaturated fatty acids, fatty acid desaturases introduce trans double bonds in fatty acyl CoAs

True or False;

Fatty acid synthesis and degradation occur at the same time

False;

they are regulated so that only one occurs at a time

The liver processes fats, carbs, and proteins.

The liver delivers lipids, glucose, and ketone bodies.

-By converting glucose to glycogen or fatty acids when levels are too high

-By releasing glucose by glycogen phosphorylation or gluconeogenesis when levels are too low

-By releasing ketone bodies as an alternative fuel

What is this picture showing?

[image]

1. It can be used to make glycogen for later use

2. It can be phosphotased to glucose to replenish blood glucose

3. It can enter the pentose-PO4 pathway, making NADPH and possibly nucleotides (ribose)

4. It can enter glycolysis with acetyl-CoA

What is the picture showing?

[image]

Ketone bodies to fuel other tissues

Cholesterol and other steroids

How does epinephrine act on the muscle?

- Increases the release of glucose-1P in glycogen

- Decreases glycolysis (liver burns fatty acids instead of glucose)

- Increases gluconeogenesis (to supply other tissues)

- Increases ketogenesis

What is this picture showing?

[image]

Showing what happens metabolically in a well fed state;

The lipogenic liver - makes TAGS and glycogen for later use

What is this picture showing?

[image]

This is showing what happens metabolically during a fasting state;

A glucogenic liver

-there is no more glycogen, so glucose must be made from amino acids;

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True or False;

Cortisol alters the kinds and levels of metabolic enzymes

How does cortisol act on the liver and the adipose tissue?

In the adipose, it releases fatty acids from TAGs

In the liver, it promotes gluconeogenesis

~45% lipids

~50% proteins

~5% carbs

True or False;

On glycerolipids, position 2 is usually occupied by a saturated fatty acid.

False;

Position 2 is usually occupied by an unsaturated fatty acid

1. Provide transport and channels for molecules to go across membrane.

2. Adhersion proteins keep tissues together

3. Receptors for signalling molecules

4. Some are required to build, maintain, and reorganize membrane

5. Surface antigens that signal "self" to the immune system

True or False;

Intergral membrane proteins span the membrane one or more times

True or False;

β barrel can have as few as 7 residues spanning the membrane, and don't show up on hydropathy plots

Arg, Lys, Glu, Asp

they are foun in the aqueous phase 

True or False;

Sugar groups are common on the inner membrane side of membrane proteins

False;

They are more common on the outer membrane

They link to Ser/Thr side chain (OH)

N-acetylgalactosamine

(GalNAc) is generally the first sugar

They link to Asn side chains (-CO-NH2), and

N-acetylglucosamine (GlcNAc) is first sugar

True or False;

Cholesteral is flexible

False;

Cholesterol is relatively rigid

- reorganization of membrane bound compartments (e.g. organelles)

- movement of membrane components and soluble "cargo" between compartments

- internalization/ recycling/ and degradation of material from plasma membrane

1. budding (fission) of the vesicle from one membrane vesicle

2. transport of the vesicle

3. tethering/docking at the target membrane (recognition)

4. fusion of vesicle and target membranes

True or false;

v-SNAREs and t-SNARES are multi spanning transmembrane proteins

False;

They are single spanning transmembrane proteins

True or False;

Diffusion occurs spontaneously from low concentrations to high

False;

Diffusion occurs spontaneously from high to low concentrations

It is exergonic (gives off energy) and happens spontaneously.

in ΔG=RT ln(c2/c1) , if c1>c2

ln(c2/c1) is negative, so

ΔG is negative

True or False;

In passive transport, transporters do not have a continuos pore all the way through the membrane like channels

True;

Instead they have a well defined binding site that can transport one (or a small exact #) molecule at a time

It describes the energy needed to transport a charged solute across an electrical gradient

z = net charge of species

F = Faradays constant (F = 96,485.3365(21) C/mol)

Δψ = membrane potential (in volts)

ΔG = RTln(c2/c1) + zFΔΨ

this means that is it additive

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• The cycle starts with the transporter dephosphorylated,

and its binding site facing inside the cell

• The Na+ binding site binds 3 Na+ ions from inside cell

• The transporter is then phosphorylated on cytosolic side,

at the expense of one ATP

• Phosphorylation induces a conformational change,

opening the binding site to the extracellular face

• The three Na+ ions are released, and two K+ ions bind

• The transporter is dephosphorylated by hydrolysis

• The transporter again changes conformation, so the

binding sites face inside the cell

• The two K+ are released

1. Signal transducers have a very high affinity for their ligands

2. Cooperation in the ligand-receptor interaction results in large changes in activity upon ligand binding

3. Once activated, enzyme cascades amplify the signal

1. they are very specific

2. they amplify the initial signal

3. the get desensitized or adapt to persisting signals

4. they intergrate conflicting signals

Heterotrimeric G-protein coupled receptors (Heterotrimeric GPCR) consists of what 3 components?

1) plasma membrane receptors with 7 transmembrane helices (e.g. epinephrine receptor)

2) heterotrimeric guanosine nucleotide-binding protein (e.g. G-protein)

3) intracellular enzyme that generates a second messenger (e.g. - cAMP, cGMP, inosito 1,4,5-triphosphate [IP3])

1. tyrosine kinase activity

2. guanylyl cyclase activity

True or False;

Nuclear hormone receptors are transcription factot that are directly activated by hormone binding

True;

these hormones are hydrophobic and fall in to 3 catergories:

1. Steroid hormones - are based on 4-linked ring structure (like cholesterol)

2. Thyroid hormones - are built from iodinated Tyr residues

3. Retinoid hormones - are derived from isoprenoids