Amino acids, nucleic acids, water & ATP Flashcards
What are amino acids?
Amino acids are the monomers from which proteins are made.
What bond forms between two amino acids in a dipeptide?
A peptide bond forms between two amino acids.
How are dipeptides formed?
Dipeptides are formed by a condensation reaction between two amino acids.
What are polypeptides?
Polypeptides are chains formed by many amino acids joined together.
What determines the primary structure of a protein?
The specific sequence and number of amino acids in the chain.
What happens during the secondary structure of a protein?
The primary structure folds into a 3D shape using hydrogen bonds, forming an alpha-helix or beta-pleated sheet.
What bonds are involved in the tertiary structure of proteins?
Disulfide bonds (strong), ionic bonds (weaker), and hydrogen bonds (easy to break).
What is quaternary protein structure?
Two or more tertiary structures that come together, sometimes with prosthetic groups.
What are examples of globular proteins?
Insulin and hemoglobin (soluble).
What are examples of fibrous proteins?
Collagen and keratin (insoluble).
What is an enzyme and what is its role?
Enzymes are globular proteins that act as biological catalysts, increasing the rate of chemical reactions.
How do enzymes lower activation energy?
Enzymes allow the formation of enzyme-substrate complexes, lowering activation energy without being changed permanently.
How do substrates bind to enzymes?
Substrates bind to the enzyme’s active site to form enzyme-substrate complexes.
What is the lock and key hypothesis?
The enzyme’s active site has a specific shape that is complementary to the substrate.
What is the induced fit model?
The enzyme changes its active site shape to better fit the substrate and improve the fit.
How does temperature affect enzyme activity?
Temperature increases enzyme activity until it denatures at high temperatures, breaking bonds.
What happens to enzyme activity at extreme pH?
Enzymes denature because bonds are broken permanently.
What happens when substrate concentration increases?
Enzyme activity increases until all active sites are full, after which it plateaus.
How does enzyme concentration affect reaction rate?
Enzyme activity increases with more enzymes but eventually becomes limited by substrate concentration.
What is competitive enzyme inhibition?
Inhibitors bind to the enzyme’s active site, competing with the substrate due to a similar shape.
What is noncompetitive enzyme inhibition?
Inhibitors bind to the enzyme at an allosteric site, altering the enzyme’s shape and making the substrate no longer complementary.
What is the structure of a nucleotide?
A nucleotide consists of a phosphate group, a pentose sugar, and an organic base.
What are the complementary base pairs in DNA?
Adenine pairs with thymine, and cytosine pairs with guanine via hydrogen bonds.
What is the difference between DNA and RNA?
DNA has deoxyribose, thymine, and is double-stranded. RNA has ribose, uracil, and is single-stranded.
What is the function of DNA?
DNA stores genetic information, protects it with base pairing, and allows for accurate replication.
What is semi-conservative DNA replication?
DNA replicates by splitting into two strands, using each strand as a template to form new identical strands.
How does DNA helicase help in replication?
DNA helicase breaks hydrogen bonds between bases, separating the strands.
What is the role of DNA polymerase in replication?
DNA polymerase joins nucleotides together through condensation reactions, forming phosphodiester bonds.
What makes water a polar molecule?
Covalent bonds between O and H cause a polar molecule, allowing it to dissolve other polar molecules.
What bonds form between water molecules?
Hydrogen bonds form between water molecules.
What are the unique properties of water?
Water is metabolite, adhesive, cohesive, a universal solvent, has a high specific heat capacity, and surface tension.
What are the uses of ATP?
ATP is used for metabolic processes, movement, active transport, secretion, and molecule activation.
What is the structure of ATP?
ATP consists of adenine, ribose, and three phosphate groups.
How is ATP synthesized?
ATP is synthesized by the addition of inorganic phosphate to ADP using energy from respiration.
Why is ATP a good energy source?
ATP releases energy in small, manageable amounts and has unstable phosphate bonds with low activation energy.
