CH 20 Enzymes Flashcards
A biological catalyst is called a(n) __________.
enzyme
Compared to an uncatalyzed reaction, an enzyme-catalyzed reaction
occurs at a faster rate
Urease catalyzes only the hydrolysis of urea, and no other substrates. This limited activity is called
absolute specificity
combination of an enzyme with the substrate
ES Complex
a structure that fits the active site of an enzyme
substrate
has a tertiary structure that recognizes the substrate
enzyme
has a ridgid substarte binding to a riged enzyme, like a lock and key
lock and key
Why do chemical reactions in the body require enzymes?
Rates of the chemical reactions are too slow without enzymes.
To what main class of enzymes does the enzyme that catalyzes the conversion of lactose to galactose and glucose belong?
hydrolase
The hydrolysis of ester bonds in triglycerides is catalyzed by a(n)
lipase
what affects the activity of an enzyme
temperature
Name the enzyme that hydrolyzes sucrose.
sucrase
A competitive inhibitor is one that
binds to the active site in place of the substrate.
an enzyme that requires a cofactor?
requires Fe3+ in the active site for catalytic activity contains riboflavin (vitamin B2 )
What vitamin may be deficient in the disease rickets?
vitamin D
What vitamin may be deficient in the disease scurvy?
ascorbic acid
What vitamin may be deficient in the disease pellagra?
niacin
within the active site, amino acid R groups catalyze the reaction to form an _____
enzyme-product complex
what factors affect enzyme activity
pH, concentration, substrate and temperature
molecules that cause loss of catalytic activity and prevents substrates from fitting into the active site
inhibitors
Some bacterial infections are treated with competitive inhibitors called
antimetabolites.
A _______ is a cofactor that is a small organic molecule such as a vitamin.
coenzyme
OVER THE HILL
Oxidoreductases, Transferase, Hydrolases, Isomerases, Lyases, Ligases
A __________ consists of a nitrogen-containing base and a sugar.
nucleoside
A __________ consists of a nitrogen-containing base, a sugar, and a phosphate group.
nucleotide
Which of the following hold two strands of DNA in an a helix?
hydrogen bonds
When DNA duplicates itself, the correct placement of the nucleotides is accomplished by
complementary base pairing
When DNA replicates, a guanine forms a base pair with
cytosine
What is the complementary base sequence for the following DNA segment?
5’-T-A-G-C-3’
3’-A-T-C-G-5’
acts as the messenger between DNA and protein production, during transcription DNA is transcribed into
mRNA
mRNA is translated into
protein
The tRNA molecules convert the information in the mRNA into amino acids in a process called
translation
The genetic code consists of sets of three nucleotides (triplets) in mRNA called _______that specify the amino acids and their sequence in the protein.
Codons
In the synthesis of mRNA, an adenine in the DNA pairs with
uracil
When mRNA is synthesized using the information from DNA, the process is called
transcription
There are three major types of RNA. What is the purpose of transfer RNA?
It interprets the genetic information and brings the amino acids to the ribosomes
The codon is found on __________, and the anticodon is found on __________.
mRNA, tRNA
In the study of genetics, the abbreviation PCR refers to
Polymerase chain reaction
what are the bases in DNA and RNA
derivatives of the heterocyclic amines pyrimidine or purine.
In DNA,
the purine bases with double rings are
adenine (A) and guanine (G).
the pyrimidine bases with single rings are
cytosine (C) and thymine (T).
In RNA,
the purine bases with double rings are
adenine (A) and guanine (G).
IN RNA,
the pyrimidine bases with single rings are
cytosine (C) and uracil (U).
In the primary structure of nucleic acids,
the nucleotides are joined by
phosphodiester bonds
What classification of protein recognizes and destroys foreign substances
Protection
What classification of proteins store nutrients
Storage
What classification of proteins carry essential substances through the body
Transport
What classification of proteins provide structural components
Structural
Amino acids have what two functional groups?
Ammonium and carboxylate
