Chapter 4 Proteins and Nucleic Acids Flashcards
Out of all the macromolecules proteins have the most diverse what?
Range of functions
What is the most abundant organic molecule in living systems?
Proteins
What do all proteins have in common?
They are all polymers of animo acids, and they are all arranged in a linear sequence
What are the traits of proteins?
Structural, regulatory, contractile, and protective
Where do proteins serve?
Transportation, storage, and membranes
What are the types of proteins?
Enzymes or toxins
What are the two ways proteins vary most?
Structure and function
How many proteins can a cell in a living system contain?
Thousands of uniquely functioning proteins
What are four examples of digestive enzyme proteins?
Amylase, lipase, pepsin, and trypsin
What is the function of digestive enzyme proteins?
They digest food by catalyzing nutrients into monomeric units
What are two examples of transport proteins?
Hemoglobin and albumin
What is the function of transport proteins?
To carry substances in the blood or lymph nodes throughout the body
What are three examples of structural proteins?
Actin, tubulin, and keratin
What is the function of structural proteins?
To construct different structures, like cyto skeletons found inside cells
What are two examples of hormone proteins?
Insulin and thyroxine
What is the function of hormone proteins?
To coordinate the activity of different body systems
What is an example of a defense protein?
Immunoglobulin
What is the function of defense proteins?
To protect the body from foreign pathogens
What are two examples of contractile proteins?
Actin n myosin
What is the function of defense proteins?
To effect muscle contraction
What are two examples of storage proteins?
Legume storage proteins and egg white/albumin
What is the function of storage proteins?
To provide nourishment in early development of the embryo and seedling
Denaturation Definition/Explanation
A change in temperature, pH, and/or exposure to chemicals results in a permanent change in the proteins shape which causes it to lose function; a process
What shape is hemoglobin?
Globular
What shape is collogen?
Fibrous
How is the shape of proteins maintained?
Via various different chemical bonds
Is shape critical to protein function?
Yes
What is an amino acid?
A monomer that makes up proteins
What is the fundamental structure of all animo acids?
A central carbon with an attached amino group (NH2), carboxyl group (COOH), and a variable R group/sidechain
What is another term for side chain?
R group
Where is the name animo acid derived from?
The amino group and acidic carboxyl group
How many animo acids are essential to humans?
10
What makes an amino acid essential?
The body’s inability to synthesize the amino acid on its own
What part of an amino acid is different from other animo acids?
The R group/side chain
What are the chemical natures of amino acids?
Acidic (positively charged), basic (negatively charged), polar, and non-polar
What determines the amino acids’ nature?
The nature of its R group/side chain
What are the 9 nonpolar amino acids?
Glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, and proline
What are the 6 polar amino acids?
Serine, threonine, cysteine, tyrosine, asparagine, glutamine
What are the 2 acidic/positively charged amino acids?
Aspartic acid and glutamic acid
What are the 3 basic/negatively charged amino acids?
Lysine, arginine, histidine
What is often used as an interchangeable term for protein?
polypeptide
What is a polypeptide?
A polymer of amino acids where the monomers are linked in linear chains
What is a protein
Polypeptide(s) that have a distinct shape and unique function
What determines a protein’s shape, size, and function?
The sequence and number of amino acids
What must happen before a protein can function completely?
It must have gone through protein synthesis and modification
What are the parts of a polypeptide?
A N terminal with an amino group and a C terminal with a carboxyl group
What type of bonds do amino acids use?
Covalent bonds called peptide bonds
What parts of the amino acids bond?
The carboxyl group of one to ethe amino group of another
Where are additional amino acids added?
To the C terminus (the last carbon)
What is a carbon-nitrogen backbone?
A peptide backbone that is identical for all proteins
What are the four levels of protein structure?
Primary, secondary, tertiary, and quandary
What is primary structure?
A linear sequence of amino acids in a protein
What is a disulfide-bond (S – S bond)
The only covalent bond formed during protein folding in tertiary structures
What determines the primary sequence?
The gene encoding the protein
What happens if there is a change in a protein encoding gene?
A different amino acid may result and be added on to a peptide chain possibly resulting in ailment
What is secondary structure?
A regular structure formed by proteins by hydrogen bonding between the amino acids
What are the most common secondary structures?
a-helix and b-pleated sheet
What do the a-helix and b-pleated sheet have in common?
Both are formed by hydrogen bonds between oxygen atoms in the carbonyl group and the oxygen in the amino group four acids further in the chain
What is tertiary structure?
The three-dimensional conformation of a protein formed from interactions between amino acid side chains
The tertiary structure is mostly made of interaction between what part of an amino acid?
R-group
What is the interaction between to like charged R groups
Repulsion
What is the interaction between two oppositely charged R groups?
Attraction in the form of an ionic bond
What happens when protein folding happens in a watery environment?
Hydrophobic R groups of nonpolar amino acids lay on the interior of the protein while the hydrophilic R’s of the poplar amino acids face out
What type of R groups interact using van der Waals forces?
Hydrophobic R groups
What R-groups interact in disulfide bonds?
Cysteine R-groups
What happens what a protein losses its shape
cease function
What is quandary structure?
An association of discrete polypeptide subunits in a protein
What stabilizes the structure of quandary structures?
Weak interaction between subunits
Catalyst
A substance that helps a chemical reaction take place
Enzyme
A protein that catalyzes biochemical reactions
What is an enzymes task?
To lower the amount of energy needed to perform a certain chemical reaction
How do enzymes complete their task?
They bind to substrates and hold them in a way to speed up creation or breakage of a bond
Is an enzyme an organic catalyst? And what does this mean?
Yes, it means all enzymes increase the rate of reaction
Substrate
The chemical reactants that bind to enzymes
Active site
The special place on an enzyme where the substrate binds to
What is at an enzyme’s active site?
A unique combo of amino acids that create an environment specific to certain substrates and their chemical reactions
What are enzyme’s known for?
Specificity
What happens to an enzyme when it faces extreme temperatures?
It may become less suited for binding substrates, and at high temperature it may denature
What happens when enzymes face extreme pH values?
It may denature
The ranges of what affect enzymes?
Temperature and pH
Induced Fit Definition
A dynamic fit between an enzyme and its substrate
What happens in induced fit?
Substrates interact with an enzyme causing a mild shift in the enzyme which confirms the ideal binding arrangement maximizing ability to catalyze the reaction
What always happens after a reaction occurs in an enzyme?
It returns to its original state
What is an enzyme’s hallmark property relating to the completion of a chemical reaction?
Remains unchanged by the catalyzed reaction
What are products released from an enzyme?
After, the chemical reaction is completed
Free Energy
The usable energy, or energy that is available to do work
What is another term for free energy?
Gibbs free energy (G)