BCH 100 Final Prep Flashcards by Devin O'Donnell

What are Nucleotides for?

-Signaling
-Carrying Chemical Energy
-Cofactor Components
-Building blocks for Nucleic Acids

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Why do we need Amino Acids?

Precursor for proteins, Biomolecules and energy

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How is an Amino acid catabolized?, What is the enzyme?

The amine group is removed by an -ketoglutarate to become glutamate and an -keto acid, Aminotransferase

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Why are Glutamine and Alanine necessary in the blood?

They carry toxic amine groups through the blood to the liver to be excreted

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Draw Urea

H2N-(C=O)-NH2

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Why does the Urea cycle happen and where does it occur?

The detoxification and exretion of excess NH4+, in the liver

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Write the Urea Cycle

Week 10 Lec 24

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Name the Essential Amino acids

Valine
Leucine
Isoleucine
Histidine
Lysine
Methionine
Threonine
Tryptophan
Phenylalanine

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What are the two major ways Nitrogen is incorporated into the food chain?

Nitrogen-fixing bacteria converting atmospheric Ns to NH4+, Nitrogen-assimilating Plants and Bacteria conveting NO3- to NO2- to NH4+

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What is Negative nitrogen balance?

If you are missing even one essential amino acid your body will keep eating through the protiens you have trying to find it, and you end up with such a large increase in Urea that you have more nitrogen leaving than coming in

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What is a Hormone?

an intercellular Chemical Messenger produced in the ductless glands of the endocrine system

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Name four hormones types and give examples

Steroids: estrogen, androgens
Polypeptides: insulin, glucagon
Amino acid derivitiives: Epinephrine (adrenaline)
Fatty acid derivatives: Prostaglandis

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What are the three different hormone systems?

Endocrine (travel through blood)
Paracrine (travel to nearby cells)
Autocrine( targets the same cell)

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How do Hormones function?

They bind to a specific receptor on or in the target cell membrane, triggering a signal cascade that can alter enzyme activity or alter gene transcription

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What are the three major classes of membrane receptors?

7-Transmembrane a.k.a. G-protien coupled receptors
Dimeric membrane recepters that recruit protien kinases
Dimeric protien receptors that ARE protien kinases

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Explain a GPCR cascade of Epinephrine

-Ep binds to the beta-adrenergic receptor -
-on the other side of the receptor in the membrane a G protien exchanges a GDP for a GTP and an alpha G dissociates from a betagamma G.
-Alpha G-GTP activates adenylate cyclase which converts ATP to cyclic AMP (cAMP), which is the second messenger that activates protein kinase A

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How is GPCR regulated?

-Reciprocal regulation
-Active glycogen breakdown
-inactive glycogen synthesis

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How is the signal cascade stopped?

No more signal
Break down of cAMP, hydrolyzed by cyclic nucleotide phosphodiesterase back into AMP
a built in timing mechanism of GTP on alpha G slowly hydrolyzing to GDP

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How is RTK activated?

Binding to an RTK receptor causes it to autophosphorylate its own tyrosine residues, phosphotyrosines allow binding and phosphorylation of the receptor substrate causing a cascade

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How is RTK regulated?

-stopping the hormone signal
-Removal of phosphates from activated proteins,

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Describe Glucagon

-29-amino acid polypeptide hormone
-Released by alpha-cells of islets of langerhans in the pancreas
-Signal for low blood sugar (starvation state)
-Binds to GPCRs on liver cells

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Describe Epinephrine

-Derived from Tyrosine in adrenal medulla
-Fight or flight hormone
-Acts on GPCRs of the liver and muscle cells

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Describe Insulin

-Peptide hormone
-Released by beta-cells of islets of langerhans (pancreas)
-Signal for high blood glucose (“fed” state)
made as preproinsulin, undergoes proteolytic cleavage
-chains held together by disulfide bonds
-Binds to RTK (NOT GPCR)

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Describe a lipoprotien and its functions

Lipoprotiens transport TAGs and Cholesteral in the blood. The protein part solubilized lipids and direct the particle, the lipid parts are the fats that need to be transported

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What are the categories of Lipoprotiens?

Chylomicrons: dietary fat (TAG) transport VLDL: very low density endogenous fat (TAG) transport LDL: low density, major cholesterol carrier in blood HDL: high density: reverse cholesterol transport

Why does the oxidation of fats yield more energy that oxidation of carbs?

Fatty acids are highly reduced

What are the ways and locations triacylglycerol used?

When broken down into glycerol: -it can enter the liver to go through glycolysis and become pyruvate or gluconeogenesis to become glucose. When broken into a fatty acid: it enters other tissues to go through beta oxidation and the citric acid cycle

Draw the beta oxidation cycle

Week 9 lec 21-22

How many NADH, FADH and GTP is made per cycle of Beta oxidation?

1NADH, 1 FADH

How many ATP per NADH and FADH?

2.5 NADH, 1.5 FADH

Where are ketone bodies made and under what circumstances?

Liver Mitochondria, ketosis happens High fat intake, low sugar, starvation and diabetes

Name 3 ketone bodies

-Acetoacetate -Acetone -Beta hydroxybutyrate

Name the 12, 14, 16, and 18 carbon fatty acids

12-Laurate 14-Myristate 16-Palmitate 18-Stearate

What is a lipid?

An organic molecule that is not soluble in water, but is soluble in organic solvents

What are the 5 main classes of fatty acid and their purposes?

1. Free fatty acids: Fuel 2. Triacylglycerols: Storage or fatty acids 3. Phospholipids: Membrane lipids 4. Glycolipids: membrane partly made of carbohydrates 5. Steroids: polycylic hydrocarbons with a variety of functions

How and where is fatty acid activated?

Fatty acid is activated by acyl-CoA synthase and occurs in the cytoplasm

How does activated fatty acid get into the mitochondria and what are the steps?

The carnitine shuttle transports fatty acid into the mitochondria: 1. carnitine acyltransferase -1 (CAT-1) transfers acyl to the carnitine 2. Carnitine translocase carries acylcarnitine into the matrix 3. CAT-2: transfers acyl from carnitine to CoASH to regenerate Acyl-CoA

Draw The Calvin Cycle

Week 8 lec 19

Define Photosynthesis

Using light energy to biosynthesize sugar

Draw the light dependent photosystem

Week 8 lec 19 (lower part)

Draw the electron transport chain

Week 7 lec 18

Whats the difference between a Nucleosides and Nucleotides?

Nucleosides: Base + sugar Nucleotides: Base + sugar + Phosphate

Whats the difference between Purines and Pyrimidines?

Purines: Two heterocyclic rings Pyrimidines: one Heterocyclic ring

Name the Purines

Purine, adenine, and Guanine

Name the Pyrimidines

Pyrimidine, Cytosine, Uracil, Thymine

What are the differences between purine and pyrimidine biosynthesis?

Purine synthesis: Start with sugar, build ring on ie Pyrimidine synthesis: Build base ring, add sugar

What are the two way to make nucleotides?

-Salvage pathways where you recycle nucleoside -De Novo synthesis where you make them from scratch

What is the committed step of Pyrimidine synthesis

Aspartate Transcarbamoylase

What is the committed step of Purine Synthesis

PRPP-gln amidotransferase

Draw Orotate

6 atom ring: 1N,2C,3N,4-6C

Draw Glycine

Amino acid slide

What do enzymes change and not change?

They change delta-G double dagger, the transition energy also known as the activation energy. They do NOT change delta-G (also written delta-g rxn), the reaction energy

On a reaction rate graph, what do the following mean? V0 Vmax K m K cat

V0: initial velocity Vmax: Maximum Velocity K m: Substrate concentration at 1/2 Vmax K cat: turnover number

On a Lineweaver-Burk graph what are: X axis: Y axis: X-intercept: Y-intercept: Slope:

X axis: 1/[S] Y axis: 1/V0 X-intercept: -1/Km Y-intercept:1/Vmax Slope: Km/Vmax

How do the three types of inhibitors affect the Lineweaver-Burk graphs?

Competitive shift slope but keeps y-intercept Uncompetitive shifts the intercepts but not the slope Noncompetititve shifts the slope but not the x-intercept

What naming monosaccharides, what does D and L mean?

From the last carbon, is the nearest alcohol up the chain to the right (D), or the left (L)

whats the name of a 5-ring sugar and a 6 ring sugar?

5: Furanose 6:Pyranose

How are Oligosaccharides connected?

O-glycosidic bonds

Define Maltose structure

Two cyclic glucose connected by a alpha(1,4) bonds

Define Lactose Structure

cyclic Galactos and cyclic glucose connected by beta(1,4) bond

Define Sucrose structure

Cyclic glucose and cyclic fructose connected by alpha(1,2) bond

Draw Fructose

Sugar structure handout

Draw Galactose

Amino Structure handout

What is the order for Purine nucleotide synthesis?

-PRPP synthetase -Glutamine-PRPP amidotransferase -Inosinate Formation -Ribonucleotide Reductase

Draw Succinate

COO- _CH2_CH2_COO-

Draw Pyruvate

COO-_C=O_CH3

BCH 100 Final Prep Flashcards

(66 cards)