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WorksheetsProteins and enzymes
Total questions: 30
Worksheet time: 25mins
Which structure changes in the different amino acids?
Amino acids are organic compounds that contain 2 functional groups & a side chain specific to each amino acid. What are those 2 functional groups ?
Amine & Ketone group
Ketone & Aldehyde group
Amine & Carboxylic group
Carboxylic & Amide group
Are these statements about amino acids true or false?
In the solid state amino acids exists as zwitterions
true
false
This property of amino acids refers to their ability to act as an acid or a base.
zwitterionic
chirality
UV absorptive
amphoteric
What's the correct definition of these keywords?
zwitterions
Amino acid molecules with a negative charge on the amine group in the form of COO- and a positive charge on the carboxylic acid group in the form of NH3+
Amino acid molecules with a positive charge on the amine group in the
form of NH3+ and a negative charge on the carboxylic acid group in the
form of COO-
Amino acid molecules with a negative charge on the amine group in the form of NH3- and a positive charge on the carboxylic acid group in the form of COO+
Which of these structures is a zwitterion?
Why are many enzymes soluble in water?
They contain large numbers of hydrogen bonds
They contain many amino acids with hydrophilic side chains
they contain an active site
They contain many amino acids with hydrophobic side chains
Amylase is an enzyme found in saliva that helps break down starch in your mouth. In this chemical reaction, starch would be an example of a(n)
substrate
enzyme
active site
product
In what ways do enzymes help a cell carry out its chemical reactions?
Enzymes lower the amount of reactants needed for the reaction to occur.
Activation energy and the rate of reaction are both increased by enzymes.
Enzymes speed up chemical reactions by lowering the activation energy needed.
Enzymes slow the reaction down by increasing the amount of energy produced.
Which type of bonding is primarily responsible for the primary structure of a protein?
Hydrogen bonding
Ionic bonding
Disulfide bonding
Peptide bonding
Which level of protein structure is characterized by α-helices and β-pleated sheets?
Primary
Secondary
Tertiary
Quaternary
What happens to an amino acid in a strongly acidic solution?
It becomes negatively charged
It remains neutral
It gains a proton on the amine group
It loses a proton from the carboxyl group
Which condition is required for the hydrolysis of proteins into amino acids?
Cold water and stirring
concentrated aqueous acid or alkali and heat
Anhydrous conditions
Presence of a strong oxidizing agent
What is a stereospecific active site?
The active site can change shape
It will react with either enantiomer
The active site can produce either enantiomer product
It will only react with 1 of a pair of enantiomers
A peptide bond is formed by:
addition reaction
condensation reaction
hydrolysis reaction
neutralisation reaction
The bond formed between two amino acids is a:
glycosidic bond
disulfide bond
peptide bond
hydrogen bond
Disulfide bonds form between...
two glycine residues
two cysteine residues
lysine and arginine
two peptide bonds
The isoelectric point pf an amino acid is the pH at which:
the amino acid is fully protonated
the amino acid is fully deprotonated
the amino acid has no overall charge
the amino acid is hydrolysed
Enzymes are
fibrous proteins
globular proteins
The region of the enzyme where the substrate binds is called the:
allosteric site
peptide region
tertiary region
active site
In the lock and key hypothesis, what is the substrate?
the reacting molecule
the active site
the enzyme
the cell
Denaturation of a protein involves:
breaking of peptide bonds
breaking primary structure
disruption of secondary and tertiary structure
hydrolysis of amino acids
Haemoglobin is an example of a....
primary structure
secondary structure
tertiary structure
quaternary structure
Which is NOT an example of a prosthetic group?
Fe2+
phosphate group
glycine
sugars
Which statement about enzymes is not correct?
The tertiary structure of an enzyme influences which molecules can bind to the active site.
The action of enzymes can be inhibited by a molecule or ion that binds to the active site.
Enzymes work equally well on both optical isomers of a substrate.
Computers can be used to design drugs to block active sites on enzymes.
