Glutamate and α-ketoglutaric acid, as well as oxaloacetic acid and aspartic acid, are especially important in carbohydrate metabolism because:
They allow a way to add intermediate molecules to the TCA cycle
Tyrosine is a non-essential amino acid because we can synthesize it from:
Phenylalanine
S-Adenosylmethionine is used in synthetic reactions to:
Provide methyl groups for synthesis reactions
We need daily supplies of many vitamins, including folic acid. For what purpose or purposes do we need folic acid?
To carry one-carbon fragments during metabolism
Transamination of amino acids results in products called:
α-keto acids
Ketogenic amino acids are broken down to acetoacetate or
acetyl-CoA (or Pyruvate)
The amino acids Ala, Cys, Gly, Ser, and Thr are all degraded to the metabolite
pyruvate
Which of the following glycolytic intermediates is the common precursor to serine, cysteine, and glycine?
3-phosphoglycerate
The neurotransmitters DOPA, dopamine, epinephrine, and norepinephrine are synthesized from the amino acid
tyrosine
Nitrogenase carries out the reaction that reduces nitrogen to
NH3
When glutamate is oxidatively deaminated by GDH, the products include
NAD(P)H + H+, NH4+, and a-ketoglutarate
In which cellular compartment does the following reaction take place?
arginine —> urea + ornithine
cytosol
In which cellular compartment does the following reaction take place?
ornithine + carbamoyl-phosphate —> citrulline
mitochondrial matrix
In the reaction depicted below, choose the right answer:
A)The reaction is involved in the protein synthesis where 1=carbamoyl synthetase, and 2=carbamide phosphate
B)The reaction is the committed step of the urea cycle where 1=carbamoyl phosphate synthase, and 2=carbamoyl phosphate
C)The reaction is a side product of the urea cycle, and 1=carbamoyl phosphate synthase, and 2=carbamoyl phosphate
D)A) and C)
The reaction is the committed step of the urea cycle where 1=carbamoyl phosphate synthase, and 2=carbamoyl phosphate
The metabolite chorismate
is an important intermediate in the production of Trp, Tyr, Phe
Which of the following reactions is catalyzed by adenylate cyclase?
ATP → cAMP + PPi
How do steroid hormones influence gene expression?
They bind receptor in the cytosol. These complexes then migrate to the nucleus where they bind hormone response elements to affect transcription
Phospholipase C cleaves PIP2, generating
IP3 and DAG (inositol-1,4,5-trisphosphate and 1,2-diacylglycerol)
During fasting and prolonged starvation, skeletal muscle
Protein is degraded to provide amino acids to the liver for gluconeogenesis
Which of the following are effects of insulin secretion?
A)Muscle and adipose tissue are stimulated to take up glucose;
B)Gluconeogenesis is inhibited in the liver and kidney;
C)Synthesis of glycogen, proteins, and triacylglycerols are stimulated, promoting cell growth;
D)A and B;
E)A, B, and C
E)A, B, and C
The functions of the kidney include all of the following except
A) Blood pH regulation;
B) Body water regulation;
C) Reabsorption of electrolytes, sugars, and amino acids from the urinary filtrate;
D) Filtration of blood plasma which results in the excretion of water-soluble waste products;
E) Production of urea from ammonia
Production of urea from ammonia
A simple system for information flow is composed of three components : reception, transduction and response. In multicellular organisms hormones play a role in which phase?
Reception
The IP3 receptor
Is a calcium channel
What types of molecules serve as the starting materials for synthesis of uric acid?
Purine bases
Ubiquinated proteins are transferred to large proteolytic machines for cleavage to smaller fragments. The proteolytic machine is known as a:
Proteasome
Calmodulin is a
Calcium-binding protein
The liver performs all of the following functions except
Storage of energy in the form of fat
Degradation of proteins is facilitated by a process known as:
Ubiquination
Brain tissue normally consumes glucose, but when glucose levels are low, nervous tissue can also consume:
β-hydroxybutyrate and acetoacetic acid
Peptide hormones which bind to G-protein-coupled receptors stimulate the activity of adenyl cyclase, producing a second messenger called:
Cyclic-3'5'-adenosine monophosphate
