General Biochemistry Flashcards
Macromolecules capable of speeding the the rate of a reaction without being used up at the end of the reaction are called __________________
Enzymes
Enzymes are otherwise called _____________
Biocatalysts
Enzymes are different from catalysts in the sense that ________________
Enzymes function in a biological system
Catalysts function in a non-living system
Enzymes only speed up the rate of a reaction
Catalysts speed up or slow down the rate of a reaction
Enzymes can be denatured by changes in ___________ and ______________
Temperature
PH
Enzymes occur below ____________°C
100
What is the catalytic power of enzymes?
10⁶ to 10¹²
Which is true of enzymes
a) Undergo physical changes during a reaction and remain that way at the end of the reaction
b) Undergo no changes at the beginning of a reaction but changes toward the end
c) Undergo physical change during a reaction and changes back to its original form at the end of the reaction
C
Enzymes undergo physical changes during a reaction but revert back to their original forms at the end of the reaction
Enzymes exhibit their catalytic effects on substances known as _______________
Substrates
The fundamental structural units of all proteins are __________________
Amino acids
Peptide bonds are _____________ bonds
Covalent
Proteins contain __________% of carbon
50-55
Proteins contain ____________% of nitrogen
15-18
Name the 10 essential amino acids
Methionine
Arginine
Tryptophan
Threonine
Histidine
Isoleucine
Leucine
Lysine
Valine
Phenylalanine
Mnemonic: vote MATT HILL for VP
Name the 10 Non-essential amino acids
Alanine
Asparagine
Aspartate
Proline
Serine
Cysteine
Tyrosine
Glycine
Glutamine
Glutamate
Mnemonic: Always Allow Annoying People Sit Close To Gi-Gantic Girls
Amino acids in nature that do not occur in proteins are called ______________
Non-protein amino acids
4 physical properties of amino acids
Some are tasteless
Some have sweet flavor
They are white crystalline structures
Soluble in water
Insoluble in non-polar organic solvents
High melting point
Amino acids contain both acid and base and can react with both of them to give water.
This is the ________________ nature of amino acids
Amphoteric
Amino acids with both negative and positive charges are called ____________
Zwitterions
**Tip: Remember “Twitter Ions”
The PH where amino acids have no tendency to move to a positive for negative electrode is called ______________
Isoelectric PH
Peptide bonds are formed between _________________
The carboxylic group of one amino acid and the amino group of the other
A typical amino acid has 5 components
Central carbon
A- Amino group
R- Group (Side chain)
C- Carboxylic group
H- Hydrogen atom
Mnemonic: Carbon - ARCH
Amino acid structures differ due to differences in their ____________
Side chains
________________ is a commonly occurring tripeptide found in living organisms used for detoxification purposes
Gluthatione
______________ is a nanapeptide in the body that induces labor in pregnant women
Oxytocin
____________ is a nanapeptide in the body that controls blood pressure
Vasopressin
______________________ is a Dipeptide commercially used as a sweetener for diabetics
L-Aspartyl-L-phenylalanine
What are the building blocks of proteins?
Amino acids
The physiological PH of amino acid is ___________
7.4
Proline is the only __________ amino acid
Cyclic
Aromatic amino acids are _______________, ______________ and _____________
Phenylalanine
Tyrosine
Tryptophan
Mnemonic: Pray Ten Times
Aliphatic amino acids are _______, __________, ____________, ___________, ______________
Glycine
Leucine
Alanine
Valine
Isoleucine
Mnemonic: GLAVI
A peptide formed between 2 amino acids is called _______________
Dipeptide
A peptide formed between 3 amino acids is called _______________
Tripeptides
A peptide formed between a few amino acids is called _______________
Oligopeptides
A peptide formed between many amino acids is called _______________
Polypeptide
__________ amino acid forms hormones like adrenaline, norepinephrine, thyroid hormones and melanin
Tyrosine
Amino acids that are converted to carbohydrates are called_______________
Glycogenic amino acids
Niacin is Vitamin B3 and it is synthesized by what amino acid?
Tryptophan
____________ and ___________ amino acids help in the synthesis of bile salts
Glycine
Cysteine
Serotonin is formed from which amino acid?
Tryptophan
_____________ amino acid is used for the synthesis of haem
Glycine
Histidine turns to _____________ upon decarboxylation
Histamine
Cysteine and methionine are sources of _____________
Sulfur
Substances derived from amino acids are called _____________
Amino acid derivatives
Gluthatione
Betaine
Alpha-ketoglutarate
Histamine
Dopamine
GABA
The above are examples of ____________
Amino acid derivatives
What type of amino acid can be synthesized in the body
a) Essential
b) Semi-Essential
c) Non-Essential
Non-Essential amino acids
Oligosaccharides contain _____________ monosaccharides
2-10
‘Two monosaccharides joined covalently by an O-glycosidic bond’
The above is a ______________
Disaccharide
Disaccharides are homogenous and not heterogeneous
True/False
False
Disaccharides can both be homogeneous as seen in maltose and heterogenous as seen in sucrose and lactose
What are enzymes?
Enzymes are proteins that alter the rate of a metabolic reaction in a biological system while not being used up at the end of the reaction.
Enzymes function in a biological system as ________________ function in a non-living system
Catalysts
Enzymes are otherwise called ________________
Biocatalysts
Enzymes can be denatured by change in _______________ and _______________
PH and Heat
Enzymes occur below ___________°C
100
What is the catalytic power of enzymes?
10⁶ - 10¹²
Enzymes exhibit their catalytic effects on substances called _____________
Substrates
Enzymes are said to exhibit Absolute specificity in what situation?
When they catalyze only one particular reaction
_____________________, ____________________, and __________________ are specificity of enzymes
Absolute
Group
Optical
Enzymes are said to exhibit Group specificity in what situation?
When they act on substrates with a specific functional group
Enzymes are said to exhibit optical specificity in what situation?
When enzymes are specific to the substrates and their optical configurations
Cite an example of Optical specificity
L-amino oxidase acting on L-amino acid but not on D-amino acid.
D-glucose oxidase acting on D-glucose but not on L-glucose
L-lactate dehydrogenase acting on L-lactic acid but not on D-lactic acid
Cite an example of Group specificity of enzymes
Pepsin
Trypsin
Chymotrypsin
Cite an example of Absolute specificity
Glucokinase acting on glucose to form glucose-6-phosphate
Enzymes are classified into 6 in what order
Oxidoreductases
Transferases
Hydrolaces
Lylases
Isomerases
Ligases
Mnemonic: OTHLIL
Enzymes that catalyze oxidation and reduction reactions are classified as ________________
Oxidoreductases
Enzymes that _____________________ are classified as transferases
Catalyze transfer of chemical groups from one compound to another
Enzymes that catalyze the hydrolysis of a bond are classified as _______________
Hydrolaces
Lylases are enzymes that _________________
Catalyze the breaking down if a bond without catalysis
Enzymes that catalyze the formation of an isomer of a compound are classified as ________________
Isomerases
Ligases are enzymes that catalyze ____________________
The association of two molecules
The minimum extra energy required by a reactant to get converted to a product is termed _______________
Activation energy
State Fischer’s Lock and Key theory?
The active site of an enzyme has a conformational shape that compliments the shape of the binding substrate
What is the active site of an enzyme?
This is the part of the enzyme where substrate molecules bind and a chemical reaction takes place.
What is the Allosteric site of an enzyme?
This is the part of an enzyme that inhibits the activity of the enzyme by changing the conformational shape of the active site.
State Koshland’s induced-fit theory
The active site of an enzyme will undergo a conformational change to attain an optimal fit for the binding substrate.
It is an enzyme-substrate interaction.
The protein part of an enzyme is called ____________
Apoenzyme or Apoprotein
A complete active enzyme is called __________________
Holoenzyme
The non-proteinous parts of an enzyme are called _________________
Co-factors
The non-proteinous part of an enzyme are of two types. __________________ and _______________
Organic part called Coenzymes
Inorganic part called Ions
What are metalloenzymes?
These are enzymes with a definite amount of metal ions that are retained throughout
What are isoenzymes?
These are enzymes that exist in different forms within a single cell or species of an organism
Isoenzymes are otherwise called ________________
Isozymes
5 uses of enzymes
Laundry
Beverages
Altering metabolic reactions
Diagnosis of diseases
Used in drug and pharmaceutical companies
Used in manufacturing industries
What are nucleotides?
Building blocks of amino acids
Nitrogenous base + Ribose = ?
The above reaction would yield a _______________
Nucleoside
Nitrogenous base+ Ribose + Phosphate group= ?
The above reaction would yield a __________________
Nucleotide
_________________ and _________________ are nitrogenous bases that make up nucleotides
Purine
Pyrimidine
The major bases of Purine are?
Adenine
Guanine
The major bases of pyrimidine are?
Cytosine
Uracil
Thymine
The minor bases of purine are?
Xanthine
Hypoxanthine
What is a Ribose?
A Ribose is a 5 carbon sugar that helps differentiate between DNA and RNA
___________________ base is formed from a hexagonal and pentagonal structure
Purine
Tip* Number the structure in an anticlockwise manner from 10 o’Clock and then clockwise from 12 o’Clock
______________ is formed from adding an amino group to position 6 of the Purine parent structure
Adenine
Tip* NH² signifies an Amino group
Guanine is formed from oxidizing position _______ and adding an amino group to position _______ of the parent structure
Oxidizing position 6
Amino group to position 2
Tip* NH² signifies an amino group
O denotes oxidization
The oxidant collects the double bond
________________ base is formed from a hexagonal structure
Pyrimidine
Tip* Structure is numbered in a clockwise manner from 6 o’Clock
Cytosine structure is formed from the pyrimidine parent structure by _______________
Oxidizing position 2
Adding an amino group to position 4
____________________ structure is formed by oxidizing both positions 2 and 4 and methylating position 5 of the pyrimidine parent structure
Thymine
___________________ structure is formed from oxidizing positions 2 and 4 of the pyrimidine parent structure
Uracil