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Practice Exam III Part I (pages 1-6)
The process of breaking down proteins into amino acids is called _______________.
The process of forming proteins from amino acids is called ________________.
concentration, inhibitors, phosphorylation/dephosphorylation
Name three ways that the process of catabolism and anabolism can be changed.
Pepsin, Trypsin, Chymotrypsin, Carboxypeptidase, Elastase
After proteins are ingested, what 5 enzymes are we concerned with?
Which of the five enzymes is NOT an endopeptidase?
Pepsinogen, drop in pH
What does Pepsin start out as? What is this process activated by?
Trypsin, Chymotrypsin, Carboxypeptidase, and elastase
Which of the enzymes come from the pancreas?
Cleaves next to carboxyl terminal
Cleaves next to small amino acid
Cleaves next to basic amino acids
Cleaves next to aromatic amino acids
Trypsinogen, Chymotrypsinogen, procarboxypeptidase, proelastase
Name the Zymogens related to these enzymes:
Which enzyme could we survive on by itself if we had to?
Of the four Zymogens, which cannot be broken down by Trypsin?
What is the process of activating a Zymogen to an enzyme called?
What is Proteolysis catalyzed by?
Trypsinogen --> Trypsin is a: FAVORABLE/UNFAVORABLE reaction?
What has a built-in Trypsin inhibitor?
Name an enzyme that can activate trypsinogen to create trypsin.
Protein synthesis, transamination, and deamination.
Intracellularly, what three things can happen with amino acids?
What is this an example of?
Alphaketoacid + amino acid <----> different amino acid + different alphaketoacid
Which amino acid(s) are similar to oxaloacetate?
Which amino acid(s) are similar to pyruvate?
Which amino acid(s) are similar to alpha-ketoglutarase?
Phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, arginine, leucine, lysine.
Name the 10 essential amino acids:
NH4 and an alpha-keto acid. Urea and Krebs
When an amino acid undergoes deamination, what are the two products? What happens to each of these products?
Starch, lactose, sucrose
What are three sources of glucose?
What is a biproduct of feeding the Kreb cycle with Alanine and Glutarate and other amino acids? What is this converted to in mammals?
Mitochondria AND cytosol
Where does the urea cycle occur?
What is the starting point of the urea cycle?
Ornithine, Carbonyl phosphate, Citruline, Aspartate, Arginosuccinate, Fumarate, Arginine, Urea.
Nemonic device for remembering urea cycle: Ordinarily
Which step of the urea cycle does not show up in mammals?
In which step does the urea cycle feed into the Krebs cycle?
Carbonyl Phosphate and Citruline
Which steps of the urea cycle occur in the mitochondria?
One of the nitrogens in urea enters the urea cycle as part of aspartate, what is the form of the other nitrogen as it enters the urea cycle?
The aspartate that enters the urea cycle is produced by the transamination of an amino acid and an alphaketoacid. Name the alphaketoacid.
Deamination of alanine produces what alphaketoacid?
Can donate an amine group, energy source
What are the two major characteristics of glutamate?
Glu --> alpha ketoglutarate + NH4 + is a REDUCTIVE/OXIDATIVE reaction. NADH is what has been REDUCED/OXIDIZED
NH4 + alphatetoglutarate + NADPH -----> Glu + NADP is common in: MAMMALS/BACTERIA
What are all of the Glu reactions catalyzed by?
Glutamate, alpha-keto acid
Glutamine has two amines that can be donated. What happens if we transaminate just one? What happens if we transaminate both?
_____________ + Glu ----> Alpha-ketoglutarate + Alanine
_____________ + Glu -----> Alpha-ketogluatarate + Aspartate
Synthesis, inhibition, phosphorylation/dephosphorylation
Citrase (from Krebs) is an irreversible reaction. What processes can irreversible reactions be regulated by?
T or F: The formation of alphaketoglutarate from Glu releases energy that is useable by the cell.
T or F Cells in Andy can directly aminate glutamate with ammonia.
T or F Cells in Andy can directly aminate alphaketoglutarate with ammonia.
3 phosphoglycerate, glycolysis
Serine can be produced from ______________ which is an intermediate in ___________.
T or F Synthesis of Ser usually coincides with high pyruvate kinase activity.
3 ATP, 2.5 ATP, 6 ATP
In Glutamate ----> Proline:
How many ATP are lost in the 1-2 step?
How many ATP are lost in the final step?
What is the net ATP lost?
T or F: we go through transamination for energy.
Glu is REDUCED / OXIDIZED in the formation of Pro. (choose one)
2 ATP (from AMP)
How many ATP equivalents are required to form a bond between an amino acid and a tRNA?
The bond between an amino acid and a tRNA molecule is what type of bond?
What molecule carries the information that a ribosome uses to synthesize the correct sequence of amino acids?
tRNA aminoacyl synthase and pyrophosphatase
What enzymes catalyze the formation of a bond between an amino acid and a tRNA?
T or F: the energy for the synthesis of proteins occurs because of the reactions in tRNA synthetase.
T or F: the subunits of a ribosome are separate unless they are against mRNA
What reads the amino acid when it enters the ribosome?
What is hydrolyzed during the process of translation?
Elongation factor G
What uses GTP in order to undergo a conformational change?
What is the minimum amount of GTP lost in order to undergo translation?
T or F: as a peptide is being synthesized, we do not see secondary structure immediately.
T or F: other proteins called "chaperones" come in and bond to this protein until it is ready to fold.
What are lipids unified by?
T or F: double bonds in a fatty acid are always trans in mammals.
T or F: if a fatty acid contains double bonds, it is unsaturated.
T or F: a saturated triglyceride usually packs together to avoid H2O.
F, F, T
T or F: a saturated triglyceride tends to be a solid at fridge temperature.
T or F: a monounsaturated triglyceride tends to be solid at room temperature.
T or F: a polyunsaturated triglyceride tends to be solid at less than freezing.
What do you call a molecule composed of three fatty acids and one glycerol?
What molecule keeps a protein that is in the process of being synthesized from folding prematurely and incorrectly?
How many total ATP are required to form a peptide bond during translation AND move the ribosome to the next position on the mRNA.
Elongation factor G and chaperones
Two proteins that are GTPases are needed for translation, what are they?
RNA and protein
What macromolecules make up a ribosome?
T or F: All of the Fatty Acid chains on a triglyceride have to be the same length.
Hydrolysis of ester bond
How do we make triglycerides hydrophilic?
2 FA + 1 monoglyceride
What is the product of hydrolysis of ester bonds of the triglyceride?
Triglyceride breaks down, goes into a cell, reforms as triglyceride as a storage form until it is needed for energy, then is broken down into 3FA + glycerol by a process called _____________.
T or F: The cell membrane by weight is 50% phospholipids.
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