Molecular Biology Flashcards
polymer
macromolecule
large organic compound
contains repeating atom groups
4 types of polymers found in living organisms
carbohydrates
lipids
proteins
nucleic acids
monomer
small and repeating organic groups that covalently bond together
building blocks of polymers
defining characteristic of lipids
insolubility in water
structure of carbohydrates
contains carbonyl group
structure of fatty acid
contains carboxyl group
structure of amino acids
contains amino group and carboxyl group
structure of nucleotide
contains nitrogenous base, phosphate group, and pentose sugar
elements in carbohydrates
carbon
hydrogen
oxygen
elements in lipids
carbon
hydrogen
oxygen
sometimes phosphorus
elements in proteins
carbon
hydrogen
oxygen
nitrogen
sometimes sulfur
elements in nucleic acids
carbon
hydrogen
oxygen
nitrogen
phosphorus
sometimes sulfur
monomer of carbohydrates
saccharide
monomer of lipids
fatty acid
monomer of proteins
amino acid
monomer of nucleic acids
nucleotide
bond between monomers in carbohydrates
glucosidic link
bond between monomers in lipids
unnamed covalent bond
bond between monomers in nucleic acids
crosslink by 2 or 3 hydrogen bonds
process of formation of carbohydrates
condensation reaction between monosaccharides
process of formation of lipids
condensation reaction between fatty acids and glycerol
process of formation of proteins
condensation reaction between amino acids
process of separation of carbohydrates
hydrolysis reaction
process of separation of lipids
hydrolysis reaction
process of separation of proteins
hydrolysis reaction
condensation reaction
chemical reaction which forms water in process of combining 2 smaller molecules to form 1 larger molecule
used in formation of carbohydrates, lipids, and proteins
hydrolysis reaction
chemical reaction which uses water molecule to split 1 large molecule into smaller molecules
used in separation of carbohydrates, lipids, and proteins
metabolism
chemical reactions inside cells
sum of all reactions that occur in an organism
parts of metabolism
anabolism
catabolism
anabolism
reactions which build up larger molecules from smaller ones
requires energy (usually in form of ATP)
catabolism
reactions which break down larger molecules into smaller ones
releases energy (usually in form of ATP)
functions of carbohydrates
main fuel source for bodily functions
monosaccharide
simplest form of sugar
most basic unit of carbohydrate
disaccharide
carbohydrate composed of 2 monosaccharides bound together by glycosidic link
oligosaccharide
carbohydrate composed of relatively low number of monosaccharides bound together by glycosidic links
typically contains around 3 to 10 monosaccharides
polysaccharide
carbohydrate composed of more than 1 monosaccharide bound together by glycosidic links
α-glucose
alpha glucose
glucose molecule with downward-pointing hydroxyl group
β-glucose
beta glucose
glucose molecule with upward-pointing hydroxyl group
cellulose (and its structure)
polysaccharide formed by β-glucose molecules with alternating orientation
linked by first carbon atom to fourth carbon atom on separate β-glucose molecules
forms straight and unbranched chain
used to provide strength to cell walls of plants
starch (and its structure)
polysaccharide formed by α-glucose molecules with matching orientation
forms curved chain that can be branched or unbranched
used to store glucose in plants
glycogen (and its structure)
polysaccharide formed by α-glucose molecules with matching orientation
forms curved and branched chain
used to store glucose in humans
comparison of glucose and fructose
2 main types of lipids (and their differences)
fats (solid at room temperature)
oils (liquid at room temperature)
triglyceride
lipid composed of 3 fatty acids linked to 1 glycerol by an ester bond
length of hydrocarbon chain of fatty acids found in living organisms
usually between 14 and 20 carbon atoms
saturated fatty acid
fatty acid with single bonds between all carbon atoms
unsaturated fatty acid
fatty acid with at least 1 double bond in between its carbon atoms
monounsaturated fatty acid
fatty acid with 1 double bond in between its carbon atoms
polyunsaturated fatty acid
fatty acid with more than 1 double bond in between its carbon atoms
cis-fatty acid
unsaturated fatty acid with hydrogen atoms that are on the same side of double bond
forms a bent chain
trans-fatty acid
trans fat
unsaturated fatty acid with hydrogen atoms that are on different sides of double bond
forms a straight chain
artificially produced through partial hydrogenation of vegetable oils or fish oils
shape of cis-fatty acid
bent at the double bond
effect of shape of cis-fatty acid
bad at packing together in regular arrays
lower melting point
typically liquid at room temperature (oil)
shape of trans-fatty acid
straight
effect of shape of trans-fatty acid
higher melting point
typically solid at room temperature (fat)
functions of lipids
energy storage (as fats in animals and oils in plants)
thermal insulation
buoyancy
cell membrane structure
hormones and vitamins
structure of steroids and cholesterol
formed by 4 fused carbon rings
hydrogenated lipids
saturated fat formed by adding additional H2 molecule to an unsaturated fat
location of hydrogen bonds in water
significance of hydrogen bonds in water
gives water its unique properties
properties of water caused by hydrogen bonding
cohesion
adhesion
capillary action
cohesion
attraction of molecules of 1 kind to other molecules of the same kind
adhesion
attraction of molecules of 1 kind to molecules of a different kind
significance of cohesive properties of water
important for water transport in plants
determines surface tension of water
significance of adhesive properties of water
responsible for cappilary action
important for water transport in plants
useful in leaves (where water adheres to cellulose molecules in cell walls)
thermal properties of water
high specific heat capacity
high latent heat of vaporization
high boiling point
latent heat of vaporization
enthalpy of vaporization
amount of energy that must be added to a liquid substance to transform a quantity of that substance into a gas
cause of high specific heat capacity of water
motion of water molecules is restricted by hydrogen bonds and increased temperature is necessary to break hydrogen bonds
cause of high latent heat of vaporization of water
motion of water molecules is restricted by hydrogen bonds and increased temperature is necessary to break hydrogen bonds
cause of high boiling point of water
motion of water molecules is restricted by hydrogen bonds and increased temperature is necessary to break hydrogen bonds
effect of high latent heat of vaporization of water
evaporation of water has a coolant effect because it requires so much heat
cause of solvent properties of water
polar nature of water causes formation of shells around charged and polar molecules which prevents them from clumping together (and keeps them in solution)
hydrophilic substance
substance which is chemically attracted to water
substance which is soluble in water
type of molecules which are hydrophilic
polar molecules
particles with positive or negative charges
hydrophobic substance
substance which is insoluble in water (although it may dissolve in other solvents)
types of molecules which are hydrophobic
nonpolar molecules
particles without positive or negative charges
polypeptide
chain of amino acids
linked together by condensation reactions on ribosomes through translation
main component of proteins (sometimes only component)
oligopeptide
chain of fewer than 20 amino acids
amount of amino acids used to make polypeptides
20
part of amino acid which gives polypeptide its properties
functional group (“R group”)
role of ribosomes in forming polypeptides
linking amino acids together (one-at-a-time)
making peptide bonds between any pair of amino acids
possible number of sequences for polypeptide of n amino acids
10n
storage of polypeptide sequence code
within base sequence of a gene (using genetic code)
requires 3 bases of gene per amino acid
functions of collagen (and how)
structural (provide tensile strength in tendons, ligaments, skin, and blood vessel walls)
functions of hemoglobin (and how)
transport (transports oxygen to tissues that need it)
functions of ‘myosin and actin’ (and how)
movement (contraction of muscle fibers and movement in animals)
functions of immunoglobin
defense (antibodies which fight bacteria and viruses)
determination of conformation of protein
amino acid sequence of protein and constituent polypeptides
fibrous proteins
proteins which are formed with an amino acid sequence that prevents folding up and ensures chain of amino acids remains in elongated form
conformation of fibrous proteins
elongated
repeated structure
solubility of fibrous proteins in water
insoluble in water
functions of fibrous proteins
provide strength and support to tissues
globular protein
proteins which are formed by folding of amino acids as they are added one-by-one
conformation of globular proteins
have intricate shape
includes parts that are helical or sheet-like
solubility of globular proteins in water
nearly soluble (forms colloids)
functions of globular proteins
pigments
transportation of proteins
assist with immune system
primary uses for proteins
catalysts
muscle contraction
cytoskeletons
tensile strengthening
blood clotting
transport of nutrients and gases
cell adhesion
membrane transport
hormones
receptors
packing of DNA
immunity
biotechnical uses for proteins
enzymes for removing stains
monoclonal antibodies for pregnancy tests
insulin for treating diabetics
genome
all of the genes of a cell, a tissue, or an organism
proteome
all of the proteins produced by a cell, a tissue, or an organism
variability of genome and proteome of organism (and why)
genome is fixed (because all cells in organism have same genes)
proteome is variable (because different cells in organism make different proteins)
4 levels of protein structure
primary structure
secondary structure
tertiary structure
quaternary structure
primary structure
primary structure of protein
number and order of amino acids in polypeptide
determined by genetics (not random)
read from amino terminal to carboxyl terminal
secondary structure
secondary structure of protein
coils and folds of polypeptide which contribute to overall structure of protein
α helix
alpha helix
right-hand helix conformation of polypeptides within secondary structure of protein
contains hydrogen bond at every 4th amino acid
β pleated sheet
beta pleated sheet
side-by-side conformation of polypeptides within secondary structure of protein
connected by hydrogen bonds
tertiary structure
tertiary structure of protein
3-dimensional conformation of folds within polypeptides
held together by hydrogen bonding, ionic bonds, and disulfide bridges
quaternary structure
quaternary structure of proteins
overall structure of aggregated polypeptides into 1 fuctional macromolecule
conjugated protein
protein which includes binding of prosthetic group
denaturation
structural change in protein that results in loss of biological properties
enzyme
globular protein (often with prosthetic groups)
often called “biological catalyst”
lowers activation energy and yields faster rates for biochemical reactions
unchanged by reactions which it speeds up
catalyst
substance which speeds up chemical reactions
suffix to molecule which signifies that it is an enzyme
“-ase”
substrate
molecule upon which an enzyme acts
general equation of enzyme-catalyzed reaction
enzyme-substrate specificity
enzyme-substrate complex
ability of an enzyme to choose exact substrate from group of similar chemical molecules
active site
region of enzyme where substrate molecules bind and undergo chemical reaction
allosteric site
region of enzyme where enzyme inhibitors or enzyme effectors bind
lock-and-key theory
explanation of enzyme-substrate specificity by considering an enzyme to be a lock and a substrate to be the key which fits perfectly within
older and over-simplified explanation of enzyme-substrate specificity
induced fit theory
explanation of enzyme-substrate specificity
takes into account adaptability of shape of enzymes
enzyme activity
catalysis of reaction by enzyme
3 stages of enzyme activity
collision (binding of substrate or substrates to active site of enzyme)
occurrence of chemical reaction within active site
separation of products from active site
factors which affect enzyme activity
temperature
pH
substrate concentration
effects of temperature on enzyme activity
moderate increase in temperature causes increase in enzyme activity
excessive increase in temperature can cause denaturation of enzyme through destruction of bonds and structural changes to enzyme
effect of pH on enzyme activity
activity of enzyme is highest at its pH optimum
effect of substrate concentration on enzyme activity
increased substrate concentration causes increased enzyme activity (up to the point at which active site is occupied by maximum amount of substrate)
immobilized enzymes
enzyme attached to an inert and insoluble material so that it may be held in place
seen frequently in commercial use
advantages of enzyme immobilization
simple separation of enzyme and products so that chemical reaction can be stopped at ideal time
allows enzyme to be recycled after use
increased stability of enzymes to changes in pH
exposure of higher enzyme concentrations
enzyme inhibition
decrease in enzyme activity due to binding of chemical substance (inhibitor) to enzyme
types of enzyme inhibition
competitive inhibition
non-competitive inhibition
competitive enzyme inhibition
competitive inhibition
interruption of enzyme activity due to binding of chemical substance (inhibitor) to active site of enzyme
causes active site of enzyme to become occupied (thus substrate cannot bind to active site)
noncompetitive enzyme inhibition
noncompetitive inhibition
interruption of enzyme activity due to binding of chemical substance (inhibitor) to allosteric site on enzyme
causes active site of enzyme to change in shape (thus substrate is unable to bind to active site)
end-product enzyme inhibition
end-product inhibition
process wherein final product of enzyme activity produces non-competitive inhibitor for enzyme which aided in its production
types of nucleic acids
ribonucleic acid (RNA)
deoxyribonucleic acid (DNA)
functions of nucleic acids
determination of inherited characteristics of every living thing
carrying of information
directing of protein synthesis
DNA
deoxyribonucleic acid
nucleic acid which stores all hereditary information of an animal
stores primary structures of proteins
RNA
ribonucleic acid
nucleic acid which carries protein-coding instructions from DNA to ribosomes
nitrogenous bases of DNA
adenine
guanine
thymine
cytosine
types of nitrogenous bases in DNA
purines (adenine and guanine)
pyrimidines (thymine and cytosine)
nitrogenous base pairs of DNA
adenine and thymine
guanine and cytosine
theory of vitalism
vitalism
nullified belief that organisms are composed of organic chemicals that could only be produced in living organisms due to need for unspecified “vital force”
process of falsification of vitalism
series of discoveries (including artificial sythesis of urea)
