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what is the functional group of alcohols, aldehydes, and ketones?
alcohols= oh
aldehydes= cho
ketones= co
what are two features of amphipathic biomolecules?
polar functional groups and hydrophobic regions
why do polar molecules dissolve in water?
Because they form hydrogen bonds with water molecules
what are salt bridges?
interactions between charged amino acids
the hydrolysis of glycogen involves...
the transfer of glycosyl groups to water
Define "Ion-Product Constant for Water (Kw)"
the product of the concentrations of the hydrogen ions and hydroxide ions in water
who introduced the term pH?
Sorensen (1909)
how do we calculate the pH of a solution?
1) calculate the hydrogen ion concentration
2) calculate the base 10 logarithm of [H+]
3) pH is the negative of the value in step 2.
low pH values correspond to...
high concentrations of [H+]
high pH values correspond to...
low concentrations of [H+]
what is the expression for the dissociation constant (Ka)?
pKa= -logKa
the smaller the value of pKa...
the stronger the acid
What does the Henderson-Hasselbalch equation describe?
behaviour of weak acids and buffers
how can we observe the effect of dielectric constant on pKa?
by adding ethanol to water
why does the pKa of a carboxylic acid increase?
because ethanol decreases the ability of water to solvate a charged species
why are hydrogen bonds important in water?
they account for the surface tension, viscosity, liquid state (at room temp), and solvent power of water
which compounds can serve as hydrogen bond donors and/or acceptors?
ones that contain O or N
what does pKa express?
the strength of a weak acid
what do buffers do?
resist changes in pH when protons are produced or consumed
what are amino acids?
they are the building blocks of proteins
What are the many functions of proteins?
nerve transmission, biosynthesis of porphyrins, purines, pyrimidines and urea
what are amino acids necessary for?
infant growth, and to maintain adult health
what is the role of enzymes and polypeptiide hormones?
regulation of metabolism in the body
collagen function
forms a framework for the deposition of calcium phosphate crystals
the alpha carbon of an amino acid is...
chiral
why are amino acids colourless?
they do not absorb visible light
most proteins absorb light in the region of...
280nm
what are globular protein structure?
compact, roughly spherical and have axial ratios of not over 3
what conformation should a protein have?
functionally efficient and physically strong
water is...
an excellent nucleophile and reactant/product in metabolic reactions
what does the regulation of water depend on?
ADH, evaporative loss, hypothalamic mechanisms that control thirst
what is a dipole?
molecule with electrical charge distributed asymmetrically about its structure
why is water an ideal biologic solvent?
its strong dipole ad high dielectric constant enable water to dissolve large quantities of charged compounds (e.g. salts)
what can water serve simultaneously as?
a hydrogen donor and a hydrogen acceptor
what is the strongest force to hold molecules together?
covalent bonds
what is significant about noncovalent forces of macromolecules?
the structure, stability, and functional competence
what happens as the force of interaction between interacting species increases?
the distance between them decreases until they are separated by VDW contact distance
what is an electrophile?
An electron pair acceptor
what is a nucleophile?
An electron pair donor
what is another name for an electrophile?
Lewis acid
what is another name for a nucleophile?
Lewis base
what reactions can electrophiles undergo?
electrophilic addition and electrophilic substitution
what reactions can nucleophiles undergo?
nucleophilic addition and nucleophilic substitution
what are the three common types of hydrolysis?
salt, acid, and base
define pH
the negative log of the hydrogen ion concentration
what profoundly influences the pKa of a functional group?
the surrounding medium
structure of proteins
carboxyl groups, primary amino group, and distinctive side chain (R group) bonded to the alpha carbon atom
Why is proline unique?
has a secondary amino group
the carboxyl group dissociates to form...
a negatively charged carboxylate ion
the amino group is...
protonated
What does polar mean?
even distribution of electrons
what does the nature of the side chains dictate?
the role of the amino acid that plays in a protein
how many celenoproteins do humans contain?
two dozen
dextrorotatory...
right handed
levorotatory...
left handed
how do the -COOH and -NH3 exist?
in dynamic protonic equilibrium
amino acids may have...
positive, negative, or zero net charge
molecules with zero net charge are called...
zwitterions
pKa values express...
the strengths of weak acids
define configuration
the geometric relationship between a given set of atoms
Define conformation
3D structure of a molecule
metalloproteins contain...
tightly associated metal ions
what is biochemistry?
the study of chemical processes in living organisms
what is the objective of biochemistry?
to understand at the molecular level all of the chemical processes associated with living things
Define health
A state of complete physical, mental, and social well-being
what does health depend on?
a harmonious balance of biochemical reactions in the body
according to biochemistry, what causes disease?
abnormalities in biomolecules, biochemical reactions and processes
what is the mass number?
Number of protons and neutrons
what is the atomic number?
number of protons
why is water important in the body?
The body's vital processes take place in water; chemical reactions, blood, perspiration
why is the dipolar structure of water important?
has the capacity to form hydrogen bonds
entropic forces dictate that...
macromolecules expose polar regions to an aqueous interface and bury nonpolar regions
which three things participate in maintaining molecular structure?
salt bridges, hydrophobic interactions, and VDW forces
name three physiologic buffers?
bicarbonate, orthophosphate, and proteins
immunoglobulins function
fight diseases
what is the physiologic pH?
7.4