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- building blocks of complex lipids
- long chains of carbons with carboxylic acid
six major groups of lipids
triglycerideas, phospholipids, glycolipids, steroids and terpenes
- three carbon backbone called glycerol, attached to three fatty acids
- -store energy
- -adipocytes is made up of this
- glycerol backbone
- polar phosphate replaces one fo the fatty acids
- phosphate group lies on the opposite side of the glycerol from fatty acids
- aa with peptide bonds
- alpha helix and beta sheets
- has hydrogen bonds between carbonyl carbon and amino hydrogen
disrupts disulfide structure--tertiary
urea disrupts what forces in proteins?
- 6 C carbohydrate-->glucose (favors ring form)
- glucose has two anomers (Beta form and alpha form)
- -alpha is where the OH (1) and methoxy are on diff sides
what is glycogen
branched glucose polymer with alpha linkages
function of liver
- regulates blood glucose levels
- reform glucose from glycogen and releasing it back into the blood stream
spontaneous passive transport across a membrane via proteins
what does insulin do?
increase rate of facilitated diffusion of glucose and other monosaccharides
what do plants form from glucose?
starch (alpha linkages) and cellulose (beta linkages)
- five carbon sugar
- nitrogenous base
- phosphate group
between phosphate group of one nucleotide and 3rd carbon of the pentose of the other nucleotide
what are other nucleotides besides RNA and DNA
ATP, cAMP, NADH and FADH2
as substrate increases, the rate of the reaction
- compete with substrate by binding reversibly with noncovalent bonds to the active site
- raise the Km, but do not change Vmax.
- bind noncovalently to enzyme at a spot other than the active site and change the conformation of the enzyme.
- lower Vmax not Km
product returns to activate the enzyme
the first substrate changes the shape of the enzyme, allowing other substrates to bind more easily.
lyase and ligase
- catalyzes joining of molecule to a double bond (ATP synthase)
- ligase: requires energy from ATP
what overcomes a competitive inhibitor?
increasing the substrate concentration
what does not change the rate of enzyme catalyzed reaction?
decreasing the concentration of substrate
peptidases that function in the stomach must likely?
decrease their function in the small intestine due to decreased hydrogen ion concentration b/c small intestine is basic.
what are the three basic stages of metabolism/
- 1) macromolecules are broken into constituent parts (monosaccharides, proteins and lipids) releasing little or no energy
- 2) constituent parts are oxidized to acetyl CoA, pyruvate or other metabolites forming some ATP and reduced coenzymes (NADH, FADH2)
- 3) if oxygen is available and cell is capable of using oxygen-->TCA and ox phos to form energy
- anaerobic respiration
- breaks 6 carbon glucose to 3-carbon molecules of pyruvate.
- other products are 2ATP, inorganic phosphate and water, and two molecules of NADH from reduction of NAD+
- glycolysis occurs in cytosol (fluid of living cells)
what brings glucose into the cell?
phosphorylation of glucose-->allow facilitated diffusion
substrate level phosphorylation
- when 3 carbon molecule is phosphorylated while reducing one NAD+ to NADH.
- the resulting 3 carbon molecule each transfer one of their phosphate groups to an ADP to form ATP
- substrate level phosphorylation is the formation of ATP from ADP from the energy released from decay of high energy phosphorylated compd as opposed to using energy from diffusion.
can fructose and galactose enter glycolysis right away?
- fructose yes-->goes to fructose-6-phosphate
- galactose need to be converted to glucose-6 phosphate
what is lactose made up of
glucose and galactose
table sugar is made up of
glucose and fructose
products of glycolysis
2 ATP, two pyruvate, 2 NADH+
what does fermentation include?
- process of glycolysis
- reduction of pyruvate to ethanol or lactic acid
- oxidation of NADH back to NAD+
- NAD+ is restored as use in glycolysis
glycolysis has two stages
- six carbon stage (expends two ATPs to phosphorylate molecule
- 3 carbon stage (synthesizes two ATP for each
what are the characteristics of outer membrane of mitochondria
permeable to small molecules, both pyruvate and NADH pass via facilitated diffusion through porin
once inside the mitochondria matrix, what happens to pyruvate?
converts to acetyl CoA in a rxn that produces NADH and CO2
what are the products of each turn of the krebs cycle?
- 1 ATP, 3 NADH, 1 FADH2
- two carbons are lost as CO2
- glucose provides two turns of Krebs Cycle
how does acetyl coA begin the krebs cycle?
transfers two carbons to 4 carbon oxaloacetic acid
where are amino acids deaminated? what happens to the product
- in the liver
- may enter the Krebs cycle, chemically converted to pyruvic acid or acetyl CoA
where is the ETC? what does the first protein in the series do?
- inner membrane fo the mitochondria
- oxidizes NADH by accepting its high energy electrons
- electrons are passed down and ultimately accepted by oxygen to form water
how many ATP from ox phos? FADH2 and NADH?
36 ATPs, 2 ATP, 2-3 ATP
what is the function of Na/K ATPase?
transports 3 Na+ ions out and 2K+ ions in
kidney works with what organ to excrete acidic metabolites and regulate acid base buffer stores?
lungs (CO2 is expelled by lungs, lungs can decrease acid concentration by increasing expirations)
where are chylomicrons synthesized?
what is function of plasma lipoprotein lipase?
hydrolyzes chylomicron triglycerides to release free fatty acids which are taken up by cells (oxidized for energy or stored)
what organ synthesizes very low density lipoproteins? what is the function of VLDL?
transports triglycerides and cholesterol from liver to adipose tissue.
cholesterol can be used in the synthesis of?
- cell membranes
- vitamin D
- conjugate bile
what lipid levels increase in blood after eating a fat meal 2 hours prior?
- increase in chylomicrons
- HDL (good fat) is fairly constant
- VLDL is synthesized in the liver, precursor to LDL (which has less fat, more protein)
what happens in hypercholesterolemia
- defective cellular LDL receptors, without them, LDL will not be transported into the cell (cytoplasmic LDL low)
- without LDLs, cholesterol cannot be transported into cell (levels in plasma are high)
what happens to glycolysis where they are high levels of ATP and NADH?
negative inhibitors of glycolysis b/c they are found on product side of glucose oxidation.
what happens to pyruvate when acetyle Coa levels are low?
pyruvate concentration increases
what is the total number of FADH2 produced by glycolysis and citric acid cycle
2 moles of succinate to fumarate conversion
which lip has the highest lipid density?
- lipoproteins with low density transport mostly lipids and very little protein (VLDL transports more lipid than LDL)
what structure is unique to oxytocin?
during carbohydrate metabolism, NADH is produced in which of the following locations?
- cytosol (2) by glycolysis
- mitochondria (3) per turn of krebs cycle
what is the main function of vitamins?
what does it mean when liquid chromatography and disulfide bond disruption revealed two different effusion rates?
two different effusion rates means two different size peptide chains (heterodimer)
what determines osmolarity?
one with the greatest amount of ion concentration
what molecules would increase glycolysis?
AMP and glucose
what are isozymes?
- different forms fo the same enzyme that catalyze the same reactions but have different chemical/physical properties
- -diff aa (display diff stabilities and denaturation)
- -do catalyze the same rxn and bind to substrates with great specificity.
what can serve as initial reactants for glycolysis?
glucose and hexose
what are the products of the citric acid cycle?
- 1) NAD+ (by oxidative decarboxylation using reactions of citrate and succinyl CoA)
- 2) two carbon acetyl group from Acetyl CoA attaching to four carbon OAA to produce 6 carbon citrate. 2 carbons lost as CO2 when oxidative decarboxylation occurs
total: two C enter (acetyl groups), 2 carbons leave
how do gallstones form?
when fluid is stagnant and unmoving
where is bile produced and stored?
produced in liver and stored in gall bladder
what isa dehydrogenase
An enzyme that catalyzes the removal of hydrogen from a substrate and the transfer of the hydrogen to an acceptor in an oxidation-reduction reactions
where is NADPH produced and why?
pentose phosphate pathway, required for lipid synthesis
what is produced directly by the TCA cycle?
- produces ATP indirectly through reducing equivalents such as NADH
what is gluconeogenesis?
synthesis of glucose from non-carbohydrate precursors (at least 3 carbon backbone), but not free fatty acids
what does glyconeogenesis produce?
- G-6-P (reverse of glycolysis) can be stored as glycogen.
- -glucose-6 phosphatase delivers glucose to bloodstream
- liver and kidney are main sites of gluconeogenesis.
high blood glucose
then glycolysis and low protein phosphate (high phosphatase)
low blood glucose
means high phosphate; kinase is active and gluconeogenesis. (G-6-P)
what is the role of glucose 6 phosphatase
hydrolyzes G-6-P, creating a P and glucose, allowing glucose to be released into blood.
under what conditions does glycolysis and gluconeogensis occur?
- gluconeogensis maintains blood glucose levels, a process in which glucose is generated when blood glucose are low (kinase on glucose 6 phosphate)
- glycolysis is a process where glucose is converted into pyruvate and metabolized
- it occurs when glucose levels are high
what kind of proteins are peripheral proteins able to transport?
surface receptor, never as channels.
since Acety-Coa cannot get into the inner mito membrane, what does it do?
reacted with OAA to form citrate, which has transportor.
where are all the mitochondria genes from?
solely from the mother
what directly impacts the level of acetyl-CoA needed for fatty acid synthesis?
krebs and pyruvate dehydrogenase complex
what are reactants for fatty acid synthesis?
acetyl coA carboxylase with covalently attached biotin, catalyzes the first reaction of fatty acid synthsis. Biotin must be?
NADPH is a specialized coenzyme that is used to supply reducing equivalents to which type of metabolism?
- anabolism (reducing)
- catabolism (oxidative)
what is a protease?
- breaks down proteins and peptides
- -trypsin and chymotrypsin
hemoglobin with two beta and two alpha peptide has what kind of protein structure?
what is not a post modification of a protein?
poly a tail