4 Enzymes (Molecules, Energy, and Biosynthesis) Flashcards
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a diverse group of water-insoluble biological molecules. Fats store energy, while phospholipids and sterols are major components of cell membranes.
Lipids
What are lipids and their key functions?
Lipids are a diverse group of water-insoluble biological molecules. Fats store energy, while phospholipids and sterols are major components of cell membranes.
are polyhydroxy aldehydes and ketones with the general formula (CH₂O)ₙ.
Carbohydrates
What are carbohydrates and their general formula?
- Carbohydrates are polyhydroxy aldehydes and ketones with the general formula (CH₂O)ₙ.
- a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1
are complex, abundant organic molecules that contain at least one carboxyl group and one amino group.
Proteins
What are proteins and their basic structure?
- Proteins are complex, abundant organic molecules that contain at least one carboxyl group and one amino group.
- a naturally occurring, extremely complex substance that consists of amino acid residues joined by peptide bonds.
The storage and expression of genomic information. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base.
Nucleic acid
What are nucleic acids and their basic structure?
Nucleic acids are the storage and expression of genomic information. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base.
The two main classes of nucleic acids are __ and __.
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
What are the roles of DNA and RNA in cells?
DNA carries genetic information arranged into genes, passed from cell to cell and generation to generation. RNA translates DNA’s coded message into amino acid sequences during protein synthesis.
The process of increasing the rate of a reaction by using a catalyst, which lowers the activation energy (Ea) of the reaction but does not change the overall energy of the reactants and products. It increases the rates of both forward and reverse reactions without being consumed.
Catalysis
What is catalysis and how does it work in a reaction?
- Catalysis is the process of increasing the rate of a reaction by using a catalyst, which lowers the activation energy (Ea) of the reaction but does not change the overall energy of the reactants and products.
- Catalysts increase the rates of both forward and reverse reactions without being consumed.
There are three major types of catalysts:
- heterogeneous - the catalyst is in a different phase from the reactants.
- homogeneous - the catalyst is in the same phase as the reactants.
- enzymes.
are biological catalysts that speed up synthetic and metabolic reactions in cells by lowering the activation energy. They are proteins with specific amino acid sequences and structures.
Enzymes
- Are not used up in reactions, nor do they appear in reaction products.
- They can be denatured and precipitated with salts, solvents, and reagents.
- Despite increasing reaction rates, they are sensitive to environmental factors and maintain their catalytic properties under optimal conditions.
Enzymes
What are enzymes?
are biological catalysts that speed up synthetic and metabolic/biochemical reactions by lowering the activation energy.
What are enzymes made of?
proteins with specific amino acid compositions and sequences.
Are enzymes used up in reactions?
No, enzymes are not consumed in reactions and do not appear in the final products.
How can enzymes be denatured?
Enzymes can be denatured and precipitated by salts, solvents, and other reagents.
Why are enzymes important for cells?
Enzymes are crucial for catalyzing all synthetic and metabolic reactions, allowing life-sustaining processes to occur efficiently.
the kinetic energy required to bring reactants into a position where they can interact.
Activation energy
What is activation energy?
Activation energy is the kinetic energy required to bring reactants into a position where they can interact.
How is activation energy measured?
Activation energy is measured in calories, representing the energy required to bring all molecules in a mole of reactant to a reactive state.
What role does activation energy play in a reaction?
It is the energy barrier that must be overcome for reactants to convert into products.
Enzymes bind with a substrate to form an activated __, which leads to a lower activation energy for the reaction
enzyme-substrate complex
How much faster are enzyme-catalyzed reactions compared to uncatalyzed reactions?
Enzyme-catalyzed reactions can be 10³ to 10¹⁷ times faster than uncatalyzed reactions.
What is enzyme specificity?
- Each enzyme is specific for a certain substrate (reactant molecule).
- The ability of an enzyme to select a specific substrate from a range of chemically similar compounds
How does enzyme specificity vary?
Enzyme specificity can vary and may be stereospecific or reaction-specific.
act on a single stereoisomer, which are molecules that are chemically identical but have different functional group configurations around a central carbon atom.
Stereospecific enzymes
What does stereospecificity mean for enzymes?
Stereospecific enzymes act on a single stereoisomer, which are molecules that are chemically identical but have different functional group configurations around a central carbon atom.
refers to an enzyme producing a single product from its substrate.
Reaction specificity
What is reaction specificity in enzymes?
Reaction specificity refers to an enzyme producing a single product from its substrate.
Give two (2) examples of enzyme specificity.
General term
- Stereospecificity, where a single stereoisomer is acted on
- Reaction specificity, where a single product is formed from the reaction.
a proteolytic enzyme present in the intestine that hydrolyzes peptide bonds where the carbonyl group belongs to a phenylalanine, tyrosine, or tryptophan residue.
chymotrypsin
What is chymotrypsin and what does it do?
Chymotrypsin is a proteolytic enzyme present in the intestine that hydrolyzes peptide bonds where the carbonyl group belongs to a phenylalanine, tyrosine, or tryptophan residue.
How does chymotrypsin act on a dipeptide containing phenylalanine?
Chymotrypsin hydrolyzes the peptide bond in the dipeptide where the carbonyl group is part of phenylalanine, aiding in protein digestion.
How does chymotrypsin impact cellular energy and by-products?
Chymotrypsin reduces the energy used by the cell and decreases the build-up of toxic by-products by efficiently hydrolyzing specific peptide bonds.
How does the active site contribute to enzyme specificity?
The highly specific nature of most enzymes arises from the close and complementary fit between the enzyme and substrate at the active site, similar to a lock-and-key mechanism.
What is the structure of an enzyme molecule?
An enzyme molecule is composed of one or more peptide chains folded into a globular protein with a specific conformation.
What constitutes the active site of an enzyme?
- The active site consists of the side groups of certain amino acid residues brought into proximity by the enzyme’s tertiary structure, even if these residues are widely separated in the amino acid sequence.
- specific arrangement of amino acid residues that create a unique shape and chemical environment. These residues interact with the substrate through non-covalent forces like hydrogen bonds, ionic interactions, and hydrophobic interactions, allowing the enzyme to catalyze the reaction efficiently.
refers to the catalytic potency of an enzyme, indicating how efficiently it catalyzes a reaction.
enzyme activity
What is enzyme activity?
Enzyme activity refers to the catalytic potency of an enzyme, indicating how efficiently it catalyzes a reaction.
the number of reactions catalyzed per second by the enzyme.
turnover number
What is the turnover number of an enzyme?
The turnover number is the number of reactions catalyzed per second by the enzyme.
What happens when a substrate interacts with the active site of an enzyme?
The substrate binds to the active site, forming an enzyme-substrate (ES) complex.
What happens after the enzyme-substrate complex forms?
The product is formed and separates from the enzyme, leaving the enzyme free to catalyze another reaction.
Can the enzyme be reused after releasing the product?
Yes, the free enzyme can form a new enzyme-substrate complex with another substrate molecule.
How do enzymes enhance the probability of a reaction?
Enzymes hold substrates in close proximity to one another, increasing the likelihood of a reaction.