Exam #2 Flashcards
ionic bond
transfer of electrons between atoms; electrostatic attraction of ionized molecules
covalent bond
the sharing of electrons between atoms
glycosidic bond
oxygen bridging glucoses together; has alpha and beta orientations - alpha (hydroxyl group [OH] down) vs. beta (hydroxyl group [OH] up on one side)
hydrogen bond
weak electrostatic attraction between molecules; not very strong, but can form many at a time
ester bond
links fatty acids and glycerol in fats; creates fat molecule by forming a triglyceride
phosphodiester bond
phosphate link between sugars of nucleotides; forms through condensation reaction that removes water molecule and forms a bond, creating the sugar-phosphate backbone of DNA
amino functional group
-NH2; amino acid - weak base
name of amino functional group compound
amine (ex: glycine, which is also a carboxylic acid)
functional properties of amino group
acts as base; can pick up an H+ ion from surrounding solution
how many functional groups are there? name them
7: amino, carbonyl, carboxyl, methyl, hydroxyl, phosphate, sulfhydryl
carbonyl functional group
-C=O; ketones and aldehydes; structural isomers
what indicates a ketone?
if the carbonyl group is located within a carbon skeleton
what indicates an aldehyde?
if the carbonyl group is located at the end of the carbon skeleton
Ketose sugars
fructose
Aldose sugars
glucose
carboxyl functional group
- COOH; double bond between C and O (C=O), acidic properties due to high polarity, anion w/ minus 1 charge
hydroxyl functional group
-OH (or HO); forms alcohols, polar due to electrons being drawn more towards O atom (it has higher electronegativity), can form H bonds w/ water molecules
methyl functional group
-CH3 or H3C; all single bonds w/ C at the center; adding methyl to DNA or DNA-bound molecule can impact gene expression
phosphate functional group
-PO4; double bond formed between P and the O atom directly above it, contributes negative charge to molecule, potential to react w/ water and release energy
sulfhydryl functional group
-SH or HS; 2 can react to form covalent bond (“cross-linking” stabilizes protein structure)
what is a protein?
a species-specific polymer of amino acids w/ biological activity
why are proteins important?
all life depends on proteins; they provide cellular structure and mediate nearly all cellular functions
how does a protein form?
amino acids join to form polypeptide chains, moving from monomer to polymer status
how many sets of amino acids are there?
20
what is the structure of an amino acid?
an amino group (NH2), a carboxyl group (COOH), a hydrogen atom (H), and a variable “R” group that dictates uniqueness; all attached to a central carbon atom
what are the different levels of protein structure?
primary, secondary, tertiary, and quaternary
primary structure
the linear string of amino acids, the initial sequence
secondary structure
portions of linear chain may fold into an alpha helix OR fold back and forth into beta-pleated sheets; held together by hydrogen bonds
tertiary structure
overall shape of the protein, takes on 3D structure, results from interactions between R groups
quaternary structure
two or more polypeptide chains aggregated into one functional protein
what is denaturation?
the process in which a protein loses its function due to physical or chemical changes in the environment –> cause the protein to unravel
what are the different types of proteins?
enzymes, transport, storage, defensive, contractile, hormone-signal, receptor, structural
enzyme
protein that catalyzes chemical reactions (speeds them up by lowering amount of energy used)
ex: digestive enzymes
transport
transport substances around a cell and/or across cell membrane
ex: hemoglobin
storage
store amino acids (ex: casein, ovalbumin in egg white)
defensive
protect against disease and viruses, aid immune system (ex: antibodies)
contractile
promote movement, help form muscles, tendons, cytoskeletons (ex: actin and myosin)
structural
provide structure and support (ex: keratin, collagen)
hormone-signal
coordinate physiological activities (ex: insulin regulates blood sugar levels)
receptor
respond to stimuli (ex: nerve cell receptors)
building blocks of life
monomers; amino acids, nucleotides, fatty acids, carbohydrates/sugars
what polymer do amino acids form?
proteins, through polypeptide chains
what polymer do nucleotides form?
DNA and RNA (nucleic acids)
what polymer do fatty acids form?
lipids and fats
what polymer do sugars form?
carbohydrates, including disaccharides and polysaccharides
what are the 3 different kinds of isomers?
structural, geometric, optical
structural isomer
same empirical formula, different molecular structure due to atoms being arranged differently
geometric isomer
cis-trans; cis is same (x’s are on same side) trans is different (x’s are on opposite sides)
optical isomer
bend the plane of light in different directions; enantiomers create mirror images that cannot be superimposed onto each other
cofactor
small molecules that bind with enzymes and are necessary for enzyme catalytic function; larger molecules are coenzymes
conformation
any of the spatial arrangements of a molecule that can be obtained by rotation of the atoms about a single bond
enzyme inhibitors
selectively disrupt the action of enzymes, either by reversibly binding with the enzyme via weak electrostatic bonds or by irreversibly attaching often via covalent bonds
competitive inhibitor
competes w/ enzyme by binding at the active site
noncompetitive inhibitor
competes w/ enzyme by binding to a non-active, or allosteric, site; changes the conformational shape of the enzyme, impeding function
chaperone proteins (heat shock proteins)
help the intracellular folding of proteins; protect other proteins by changing their shapes and conformations
globular protein
any protein with a round, ball-like 3D shape
allosteric regulation
regulation of enzyme activity by the binding of a regulator molecule to an allosteric site, a receptor site separate from the active site
fibrous proteins
a protein with an elongated shape; form long, filamentous structures (ex: collagen)
Purines
one category of nitrogen-containing hetero-cyclic ring (2 rings) compounds found in DNA and RNA
Pyrimidines
other category of nitrogen-containing cyclic ring (1 ring) compounds found in DNA and RNA (ex: adenine, thymine, guanine, cytosine, uracil (replaces T in RNA))
double helix
the typical conformation of a DNA molecule in which two strands are would around each other with hydrogen bonding base-pairing between the two strands
how is an ester formed?
when an alcohol combines w/ an acid in a reaction to form an organic compound
what is Km?
the substrate concentration at which the reaction rate is at half Vmax (half of Vmax)
isoelectric point
the point on the pH scale in which a molecule exists at a neutral charge (zero charge)
what bonds are associated w/ water and how do they form?
hydrogen bonds; form when the (+) end of water molecule attracts the (-) side of another
cohesion
the attachment of water molecules to each other by hydrogen bonding
surface tension
a measure of how difficult it is to stretch or break the surface of a liquid; water has a very high surface tension
adhesion
the tendency of water to stick to other substances
heat capacity
the amount of heat required, in calories, to raise the temperature of one gram of a substance by 1.0℃; the ability of a substance to take in or give up a specific amount of heat and experience large or small changes in temperature
heat capacity of pure water
high heat capacity; 1.00 cal/g/degrees C
calorie
one calorie is the amount of heat needed to raise 1 gram of pure water by 1℃
thermal inertia
how long it takes something to approach the temperature of its surroundings; water has high thermal inertia, so takes longer to heat or cool relative to land
viscosity
a measure of a fluid’s resistance to flow that describes the internal friction of a moving liquid; how resistant a liquid is to flowing under stress
melting point of ice
0 degrees C
How much heat must be added to raise one gram of water from 0℃ to 100℃ ?
To raise one gram of water from 0℃ freezing point to 100℃ boiling point, need to add 100 calories of heat
Latent Heat of Vaporization
heat added to or removed from a liquid during evaporation or condensation that produces a change in state but NOT a change in temperature
what is the latent heat of vaporization of water?
540 cal/gram
what is the pH scale?
a numerical method for expressing the range of H+ concentrations; indicates how many H+ ions are present
3 most common shapes of bacteria
cocci (spherical), bacillus (rod-shaped), and spirochetes (spiral)
gram-staining
method for differential staining of bacteria; gram-positive stains purple-black, while gram-negative stains pink
gram-positive cell walls contain what?
peptidoglycans (protein + carbohydrates)
gram-negative walls
thinner, more membrane-like = lipopolysaccharides
peptidoglycans
polysaccharides consisting of sugars and amino acids
some pathogenic bacteria
cholera, b. coli, tuberculosis, typhoid, tetanus
chromosomes
“colored bodies” containing genetic information
2 major kinds of eukaryotic cells
metazoan cell and metaphyta cell
Metazoan cell
animal; heterotrophic metabolic feeder; NO chloroplast, cell wall, central vacuole, tonoplast, or plasmodesmata
Metaphyta cell
plant; autotrophic producer; NO lysosomes, centrioles, or flagella
importance of light microscope
allows for magnification of images up to 1000x
optical microscopy
involves diffraction, refraction, or dispersion of light interacting w/ live or prepared samples to magnify images of small objects
dispersion
separation of light into wavelengths via a prism
diffraction
change in direction of light waves through an opening or around a barrier in a light path
how are samples acquired and preserved?
killed and fixed; fixation preserves tissues and prevents degradation by forming covalent bonds within and between proteins
refraction
changes in direction of light waves as they pass from one medium to another
spur cell
red blood cell w/ spike-like projections that vary in length, width, and distribution
Microtome
tool used for embedding and sectioning samples (1 to 10 micrometer thick tissue sections)
selective staining
stains (dyes) attach to specific molecules, colorizing them
carbohydrates
structure and energy molecules
lipids
fats; structure and energy molecules; diverse group of hydrophobic molecules
proteins
wide array of functions and different structures
nucleic acids
store, transmit, and help express hereditary information
phospholipids
membrane structure (phospholipid bilayer, one side hydrophilic, the other hydrophobic due to hydrophobic tails)
steroids
sterols; membrane structure, specially w/ hormones
configuration
permanent geometry of a molecule resulting from spatial arrangements of covalent bonds in space; more strict/rigid
conformation
the surface outline or contours/3D structure of molecule, results without breaking any bonds due to free rotation about single bond and weak electrostatic forces; more free and passive
4 basic parts of cell
membrane, DNA region, protoplasm/cytoplasm, organelles
Cell membrane
selectively permeable; chooses what is allowed inside and outside of the cell while also differentiating in from out
DNA region
eukaryotes store DNA in the nucleus (control center), prokaryotes store DNA in nucleoid
Organelles
“mini organs” that are designed to perform specific functions to help the cell responsible for cellular respiration and ATP production)
Protoplasm/Cytoplasm
aqueous solution providing structure and form to cells; also called cytosol
