BioChem Flashcards
PreBoards
Naturally occur in living organisms and consist mostly of
carbon, hydrogen, oxygen and nitrogen
BIOMOLECULES
Essential for various body functions & manufactured
within the body
BIOMOLECULES
Heterogenous group of organic compounds that are
insoluble in water and soluble in nonpolar organic
solvents.
LIPIDS
Nonpolar organic solvents
Diethyl ether
Acetic acid (very common)
Benzene
Hexane
CCl4 (Carbon tetrachloride)
Ethyl acetate
Chloroform
An important source of energy
LIPIDS
Naturally occur in most plants, microorganisms and
utilized as components of the cell membrane, energy
storage molecules, insulation and hormones.
Lipids
Glycerol + Fatty Acid
Lipids
Sparingly insoluble or insoluble but soluble in organic
solvents
Lipids
Lipids make up the membrane of the cell called
Lipid bilayer
Energy-rich molecules mostly made up of hydrocarbons.
Lipids
Fatty acids, glycerol, sphingosine, and sterol are its
primary building blocks
Lipids
Fat cells known as
Adipocytes
Compose the basic structure of all cell membranes (3)
Phosphoglycerides, sphingolipids and steroids
Monomer of Lipid
Fatty acid
Fatty Acids with a carbon chain in which all carbon-carbon bonds are single bonds
SATURATED FATTY ACIDS
Fatty acids with a carbon chain in which there is a
presence of one carbon-carbon double bond
MUFAs
Fatty acids with a carbon chain in which there is a
presence of 2 or more carbon-carbon double bond
PUFAs
When carbon chain length increases, solubility
decreases
Carbon chain length and the number of double bonds
present / degree of unsaturation determines a fatty
acid’s
melting point
Unsaturated fatty acid - Melting point decreases as
degree of unsaturation
increases
Energy-storage lipids
(Triacyglycerols)
Saturated fatty acid - Carbon length increases,
melting point
increases
Membrane Lipids
Phospholipids, Sphingoglycolipids, Cholesterol
Emulsification Lipids
Bile Acids
Messenger Lipids
Steroid Hormones and
Eicosanoids
Lipid formed by the esterification of three FA to a
glycerol molecule
Triacylglycerols (TAGs)
Protective Coating Lipids
Biological Waxes
Mostly concentrated primarily in special cells known as
Adipocytes
Triacylglycerols (TAGs)
Efficient at storing energy compared to glycogen
because large quantities can be packed into a very
small volume
Triacylglycerols (TAGs)
Most Abundant type of lipid in the body
Triacylglycerols (TAGs)
Triester formed from the esterification of glycerol with
more than one kind of fatty acid molecule.
Mixed Triacylglycerol
Most biochemically important to TAGs and mixed TAG
Mixed Triacylglycerol
Semi-solid at room temperature
Fats
Generally obtained from animal sources: “animal fat”
Fats
Liquid at room temperature
Oils
Generally obtained from plant sources
Oils
Functions almost exclusively as components
of the cell membrane and are not stored
Glycerophospholipids
most abundant type of
membrane lipid
Phospholipids
A polar class of lipids
Glycerophospholipids
Also known as Lecithins
Phosphatidylcholines
Prevalent in cell membranes
Phosphatidylcholines
Waxy solid that form colloidal suspensions in water
Phosphatidylcholines
Dietary sources: Egg yolks and soybeans
Phosphatidylcholines
Also known as Cephalins
Phosphatidyethanolamines and phosphatidylserines
Lipids that contain one fatty acid and one phosphate
group attached to a sphingosine molecule and an
alcohol attached to a phosphate group
Sphingophospholipids
Found in all cell membranes and are important
structural component of the myelin sheath
Sphingomyelins
Sphingophospholipids in which the alcohol esterified to
the phosphate group is choline
Sphingomyelins
Presence of amide and glycosidic linkages
Sphingoglycolipids
Lipids that contain one fatty acid and one phosphate
group attached to a sphingosine molecule
Sphingoglycolipids
Simplest sphingoglycolipids
Cerebrosides
A C27 steroid molecule that is a component of cell
membranes and a precursor for other steroid – base
lipids
CHOLESTEROL
Can undergo saponification reaction
Sphingoglycolipids
Occur primarily in the brain
Cerebrosides
Occurs both in the gray matter of the brain, as well as
the myelin sheath
Gangliosides
Most abundant steroid in the human body
CHOLESTEROL
Serves as a precursor for several other important
steroid molecules
CHOLESTEROL
carry cholesterol from the liver to various
tissues
Low density lipoprotein (LDL)
“bad cholesterol”
Low density lipoprotein (LDL)
Carry excess cholesterol from tissues back to the liver
High density lipoprotein (HDL)
“good cholesterol”
High density lipoprotein (HDL)
Also known as “plasma membrane” because it is
responsible for separating the cytoplasm of a cell form
its surroundings.
Cell Membrane
A lipid-base structure that also controls the movement
of substance into and out of the cell
Cell Membrane
Upto 80%of the mass of a cell is lipid material consisting primarily of the three types of membrane lipids:
➔ Phospholipids
➔ Glycolipids
➔ Cholesterol
components of cell
membranes and they provide rigidity to the membrane
Cholesterol molecules
membrane protein
- Penetrates the cell membrane
Integral membrane protein
No energy is required Transport process
Passive Transport & Facilitated Transport
membrane protein
- Nonpenetrating membrane protein located
on the surface of the cell membrane.
Peripheral membrane protein
Transport process in which a substance moves across
a cell membrane by diffusion from a region of higher
concentration to a region of lower concentration
Passive Transport
● Transport process in which a substance moves across
a cell membrane, with the aid of membrane proteins
● Movements is from the higher concentration to a lower
concentration
Facilitated Transport
Transport process in which a substance moves across
a cell membrane, with the aid of membrane proteins,
against a concentration gradient
Active transport
Energy is required Transport process
Active transport
A derivative of cholesterol that functions as a lipid-emulsifying agent in an aqueous environment of the
digestive tract
Bile acids
A substance that can disperse and stabilize water insoluble substances as colloidal particles in an aqueous solution
Emulsifiers
Carries an amino acid attached to the side-chain carboxyl group with the aid of an amide linkage
Bile acids
A fluid that contains emulsifying agents secreted by the liver, stored in the gallbladder, and released into the small intestine during digestion
Bile
A biochemical substance that serves as a means of
communication between various tissues
Hormone
Produced by a ductless gland
Hormone
Control the balance of Na+ and K+ ions in cells and body fluids
Mineralocorticoids
A hormone that use cholesterol derivative
Steroid Hormone
Major classes of steroid hormones
- Regulate numerous biochemical process in the body
Adrenocorticoid hormone
Major classes of steroid hormones
- Control reproduction and
secondary sex characteristics
Sex hormones
Major mineralocorticoid
Aldosterone
○ Control glucose metabolism
○ Counteract inflammation
Glucocorticoid
metabolic precursor for most
eicosanoids
Arachidonic acid
Major glucocorticoid
Cortisol
➔ Synthesized in the largest amount by adrenal glands
➔ Exert powerful anti-inflammatory effects in the body
Cortisol
Hormone – like molecules because they are not
transported in the bloodstream to their site of action.
Their effects are exerted in the tissues where they are
synthesized
Eicosanoids
Have a very short “life”, as they are broken down into
inactive residues within seconds of synthesis
Eicosanoids
a monoester of a long-chain fatty acid and a long-chain
alcohol
Biological Wax
saturated fatty acids are present (may contain 14 – 36
carbon atoms)
Biological Wax
Alcohols found in biological waxes may either be
saturated or unsaturated (may contain 16 – 30 carbon
atoms)
Biological Wax
Weak polar head and 2 long nonpolar trails
Biological Wax
Salkowski’s test
bluish red to purple
Liebermann Burchard test
(+) = red or pink-> purple- >blue -> bluish – green colour.
uses acetic anhydride and sulfuric acid
Liebermann Burchard test
contains one amino group , one carboxyl group, and a
nonpolar side chain
Nonpolar Amino Acid
MOST ABUNDANT molecules in
the cells after water
PROTEINS
An organic compound that contains both amino (-NH2)
and carboxyl (-COOH) groups attached to the same
Carbon atom
AMINO ACIDS
an amino acid that contains one amino group, one
carboxyl group, and a side chain that is polar but
neutral
Polar Neutral Amino Acid
an amino acid that contains one amino group and two
carboxyl groups, the second carboxyl group being part
of the side chain.
Polar Acidic Amino Acids
the side chain of a polar
acidic amino acid bears
a ________ charge
negative
an amino acid that contains two amino groups and one
carboxyl group, the second amino group being part of
the side chain.
Polar Basic Amino Acid
A molecule that has a positive charge on one atom and
a negative charge on another atom, but which has no
net charge
ZWITTERIONS
the -NH3 of the zwitterion loses a proton, and a negatively charged species is formed
In basic solution
the zwitterion accepts a proton
to form a positively charged ion Zwitterions
In an acidic solution
Unbranched chain of Amino Acids
PEPTIDES
Chain of covalently linked amino acids
PEPTIDES
love hormone
OXYTOCIN
A covalent bond between the carboxyl group of one
amino acid and the amino group of another amino acid
Peptide bond
plays a role in stimulating the flow of milk in a nursing mother
OXYTOCIN
regulates uterine contractions & lactation
OXYTOCIN
regulates the excretion of water by the kidneys
VASOPRESSIN
The hydrogen bonding present is intramolecular
ALPHA HELIX
are pentapeptide neurotransmitters produced
by the brain and bind at receptor sites within
the brain
Enkephalins
occurs when there are two nonpolar side chains
close to each other
Hydrophobic Interactions
The overall three-dimensional shape of a protein that
results from the interactions between amino acid side
chains (R groups) that are widely separated from each
other within a peptide chain.
TERTIARY STRUCTURE
Compact spherical molecules that are usually water soluble.
Globular Proteins
proteins whose molecules have peptide chains that are folded into spherical or globular shapes
Globular Proteins
Can undergo denaturation
Globular Proteins
A protein secondary structure in which two fully
extended protein chain segments in the same or
different molecules are held together by hydrogen
bonds.
BETA - PLEATED SHEETS
also known as Antidiuretic Hormone (ADH)
VASOPRESSIN
can also affect blood pressure
VASOPRESSIN
- also known as Salt Bridges
- always involved in the interaction between an acidic and basic side chain
Electrostatic Interactions
- can occur between amino acids with polar R groups
- relatively weak and easily disrupted by changes in
the pH and temperature
Hydrogen Bonds
antioxidant and protects
cellular contents from oxidizing agents
GLUTATHIONE (Glu-Cys-Gly)
Protein secondary structure in which a single protein
chain adopts a shape that resembles a coiled spring
ALPHA HELIX
The hydrogen bonds can either be intermolecular
or intramolecular
BETA - PLEATED SHEETS
the strongest of the tertiary- structure interactions, result from the - SH groups of two cysteine residues reacting with each other to form a covalent disulfide bond
Covalent Disulfide bonds
Function as enzymes and intracellular signaling
molecules
Globular Proteins
Organization among the various peptide chains in a multimeric protein
Quaternary structure
- found in hair , wool, skin, horns & fingernails
- provide protective coating for organs
- mainly made up of hydrophobic amino acid residues rendering them insoluble in water
Keratin
involved in iron transport in
blood
Transferrin
regulatory hormone for controlling
glucose metabolism
Insulin
Involved in oxygen storage in
muscles
Myoglobin
found in blood vessels and ligaments
Elastins
● protein whose molecules have an elongated shape
with one dimension much longer than the others.
● have simple, regular and linear structures
● such proteins have the tendency to aggregate together
to form macromolecular structures
● provide support and & external protection
Fibrous Proteins
involved in immune
system responses
Immunoglobulins
found in muscle tissue
Myosins
found in blood clots
Fibrin
- most abundant protein in the human body - major
structural material in tendons, ligaments, blood vessels
and skin - organic component of bones and teeth
- Vit. C is needed for the synthesis
Collagen
● Is a disease that arise due to an inadequate diet and starvation.
● actually the result of a lack of protein in the diet.
● it is an acute form of childhood protein-energy malnutrition
Kwashiorkor
- also known as Beta- keratin
- consists of small amino acid residue
Silk Fibroin
Involves the disruption and possible destruction of both the secondary and tertiary structures of a protein.
Denaturation
deficiency of collagen-processing-enzymes, or from mutations in the amino
acid sequences of collagen
types I, III or V.
Ehler’s - Danlos syndrome
● Is also a heterogenous group of inherited disorders distinguished by bones that easily bend and fracture.
● Common features: retarded wound healing and a rotated and twisted spine leading a hump-back appearance
Osteogenesis Imperfecta
● Is a form of severe protein- energy malnutrition characterized by energy deficiency.
● caused by severe deficiency of nearly all nutrients, especially protein and carbohydrates
Marasmus
small organic molecule that serves as a cofactor in a conjugated enzyme
Coenzyme
Mutations in the Type II Collagen
Osteogenesis
imperfecta congenita
the active site in the enzyme has a fixed, rigid geometrical conformation. Only substrates with a complementary geometry can be accommodated at such a site, much as a lock accepts only certain keys
LOCK-AND-KEY MODEL
Also known as Brittle bone syndrome
Osteogenesis Imperfecta
Mutations in the Type I Collagen
Osteogenesis
imperfecta tarda
the inactive form of apoenzyme
proenzyme / zymoge
protein part of the conjugated enzyme
Apoenzyme
an enzyme with absolute specificity. It catalyzes the - conversion of hydrogen peroxide (H2O2) to O2 and H2O. Hydrogen peroxide is the
only substrate it will accept
Catalase
biochemically active conjugated enzyme produced from an apoenzyme & a cofactor
Holoenzyme
allows for small changes in the shape or geometry of the active site of an enzyme to accommodate a substrate. A good analogy is the changes that occur in the shape of a glove when a hand is inserted into it.
INDUCED - FIT MODEL
it adapts to accept the incoming substrate
INDUCED - FIT MODEL
group-specific; it leaves amino acids, one at a time, from the carboxyl end of a peptide chain
Carboxypeptidase
temperature at which an
enzyme exhibits maximum activity
Optimum temperature
a molecule that inactivates enzymes by forming a
strong covalent bond to an amino acid side-chain group
at the enzyme’s active site.
Irreversible inhibitor
hydrolyze phosphate-ester bonds in all types of phosphate esters
Phosphatases
slows or stops the normal catalytic function of an
enzyme by binding to it
Enzyme Inhibitor
pH at which an enzyme exhibits
maximum activity
Optimum pH
A molecule that sufficiently resembles an enzyme substrate in shape and charge distribution that it can compete with the substrate for occupancy of the enzyme’s active site.
Competitive inhibitor
Major function: components of
coenzymes
B vitamins
A molecule that decreases enzyme activity by binding to a site on an enzyme other than the active site.
Noncompetitive inhibitor
produced in the skin of humans and animals by the action of
sunlight (ultraviolet light) on its precursor molecule
Vitamin D3
combines with opsin
protein to form the visual pigment rhodopsin which further converts light energy into nerve impulses that are sent to the brain
VITAMIN A
co-substrate in the formation of structural protein collagen
VITAMIN C
A three-subunit molecule in which a pentose sugar is bonded to both a phosphate group and a nitrogen-containing heterocyclic base
NUCLEOTIDES
Biomolecules that store and transmit genetic information in the cells
Main function: Storage and expression of genetic information
NUCLEIC ACIDS
Primary function: Antioxidant – protects against oxidation of other compounds
VITAMIN E
Active in the formation of proteins involved in regulating blood clotting
VITAMIN K
○ Adenine
○ Guanine
Purine Derivatives
● primary structure of a nucleic acid
● sequence in which nucleotides are linked together in a nucleic acid
Nucleotide Sequence
Known as the “Working Copies” of DNA
RIBONUCLEIC ACID
Chemical basis of heredity & considered as
the fundamental units of genetic information
DEOXYRIBONUCLEIC ACID
○ Thymine
○ Cytosine
○ Uracil
Pyrimidine Derivatives
A biological process that occurs in all living organisms
and copies their DNA ; this is the basis for biological
inheritance
REPLICATION
● The flow of information from DNA to RNA to protein
● DNA is the repository and directs its own replication
● DNA is transcribed into RNA
● mRNA is translated into a polypeptide gene product
CENTRAL DOGMA
ENZYMES involved: unwinds the supercoils
Topoisomerases
ENZYMES involved: unwinds the DNA double helix
DNA helicase
ENZYMES involved: join lagging strand together
DNA ligase
This is a process known to produce new DNA
molecules
REPLICATION
The copying process, during which a DNA strand
serves as a template
TRANSCRIPTION
enzyme responsible for copying DNA templates
DNA polymerase
components of ribosomes, the complexes that carry out the synthesis of proteins
rRNA
ENZYMES involved: works on 5’ - 3’ direction only
DNA polymerase
intermediaries, carrying genetic information from one or a few genes to a ribosome
mRNA
these are the stop signals
UAG, UAA, and UGA
start codon
AUG
adapter molecules
that faithfully translate the information in mRNA into a specific sequence of amino acids.
tRNA
three letter word, that contains the information necessary for the synthesis of proteins
CODON
provides the template or blueprint for this process.
Messenger RNA
process when mRNA carries coded information to ribosomes
TRANSLATION
The altered information can cause changes in amino
acid sequence during protein synthesis and thereby
after protein function.
MUTATION
Errors in genetic information is passed on during transcription
MUTATION
An error in base sequence reproduced during DNA replication.
MUTATION
there is a change but the protein still codes for the same amino acid. There is no manifestation to the individual
SILENT MUTATION
A different codon is produced therefore it codes for a different amino acid
MISSENSE MUTATION
An inherited blood disorder that affects the shape of the red blood cells (a flawed hemoglobin)
SICKLE-CELL ANEMIA
Untreated individuals may give off a musty or mouse- like odor as a side effect of the build-up and excess phenylalanine in the body
Classic PKU
A stop codon is produced thereby also stopping protein synthesis
NONSENSE MUTATION
A rare genetic (inherited) condition caused by the mutation in the gene that aids in creating an enzyme known as Phenylalanine Hydroxylase. Due to this mutation, there is a phenylalanine build up in the body.
PHENYLKETONURIA
Genetic disorder that affects both the lungs and the digestive system.
CYSTIC FIBROSIS
People with this can develop a very thick and
sticky mucus in their lungs, airways, and digestive system.
CYSTIC FIBROSIS
Trisomy 21 is the most common type of
DOWN SYNDROME
an hereditary disorder of the connective tissues which results to abnormally long and thin digits. People with this syndrome may also experience or develop optical and cardiovascular defects
MARFAN SYNDROME
Genetic condition where the affected person has an extra chromosome which can cause mild to serious physical and developmental problems.
DOWN SYNDROME
Considered as a rare chromosomal disorder which affects the male population. The affected person has a total of 47 chromosomes.
XYY SYNDROME (SUPER MALE)
In some cases, affected individuals develop behavioral problems such as an explosive temper, hyperactivity, impulsivity, defiant actions, or, in some cases, antisocial behavior
XYY SYNDROME (SUPER MALE)
There were many misconceptions about this disease. It was sometimes called the super- male disease
because men with this syndrome were thought to be overly-aggressive and lacking in empathy.
XYY SYNDROME (SUPER MALE)
Are considered as the MOST ABUNDANT class of bioorganic molecules
CARBOHYDRATES
monosaccharides containing an aldehyde group
ALDOSES
Functions:
● Provides energy
● Storehouse of chemical energy
● Supply carbon atoms for the synthesis of other biochemical substances (lipids, nucleic acid,
proteins)
CARBOHYDRATES
Utilized as a primary source of energy
D-GLUCOSE
Most important in a human nutritional standpoint
D-GLUCOSE
monosaccharides containing a ketone group
KETOSES
A polymeric carbohydrate that
contain a large number of monosaccharide units joined
to the next by one or more
glycosidic bonds
POLYSACCHARIDES
Dextrose / Blood sugar
D-GLUCOSE
Contain 2-10 monosaccharide
unit covalently bonded to each
other
OLIGOSACCHARIDES
bond in a disaccharide resulting from the reaction between the hemiacetal carbon atom -OH group of one monosaccharide and an -OH group on the other monosaccharide
GLYCOSIDIC LINKAGE
grape sugar
D-GLUCOSE
Carbohydrates that contain two monosaccharides joined by a glycosidic bond
DISACCHARIDES
Play an important role in keeping blood glucose concentration within the normal range
INSULIN & GLUCAGON
● Produced as an intermediate in a hydrolysis reaction
● Contains two D-glucose
monosaccharides
● Cannot be digested by humans or ferment by yeast
CELLOBIOSE
Low blood sugar level: pancreas secretes
GLUCAGON
High blood sugar level: pancreas secretes
INSULIN
Also known as “Malt sugar”
MALTOSE
Aka “milk sugar”
LACTOSE
AKA “Brain sugar”
D-GALACTOSE
Synthesized from glucose in the
mammary glands for use in lactose
D-GALACTOSE
Present in many fruits and honey
D-FRUCTOSE
Present as a chemical marker that distinguishes types of blood
D-GALACTOSE
Most important ketohexose
D-FRUCTOSE
Aka levulose and fruit sugar
D-FRUCTOSE
Sweetest-tasting of all sugars
D-FRUCTOSE
Sometimes used as a dietary sugar
D-FRUCTOSE
a known component of RNAs and energy-rich compounds such as ATPs
D-RIBOSE
is classified as a pentose sugar
D-RIBOSE
Major sugar found in milk
LACTOSE
Produced whenever the polysaccharide starch breaks down
MALTOSE
MOST ABUNDANT out of all
disaccharides
SUCROSE
Important ingredient in commercially produced infant formulas that are designed to stimulate mother’s milk
LACTOSE
Also known as “common
table sugar”
SUCROSE
Produced commercially from
juices of sugarcane and sugar
beets
SUCROSE
These are carbohydrates that contain three to ten (3-10) monosaccharide units that are bonded together by glycosidic linkages
OLIGOSACCHARIDES
This is a non-reducing sugar
SUCROSE
● Polysaccharide containing only glucose units
● Form of stored glucose in human and animals
GLYCOGEN
Known as animal starch
GLYCOGEN
Ideal storage form for glucose
GLYCOGEN
Process wherein formation of glycogen occurs
Glycogenesis
Readily absorbs water, leading to softer stools and
frequent bowel action
CELLULOSE
Takes place when blood glucose are sufficiently high.
Glycogenesis
- Occurs primarily in the liver
- Stimulated by glucagon and epinephrine
- Glycogen is broken down into glucose to provide immediate energy and to aid in the maintenance of blood glucose levels during fasting
Glycogenolysis
Most abundant naturally occurring polysaccharide
CELLULOSE
● Straight-chain glucose polymer
● Accounts for 15-20% of the starch
Amylose
Carbohydrate metabolism starts in the
MOUTH
● Similar to cellulose in both function and structure
● Gives rigidity to the exoskeleton of crabs, lobsters,
shrimps, insects, and other arthropods
● Occurs in the cell wells of fungi
CHITIN
The major breakdown products of carbohydrate metabolism:
Glucose, Fructose, & Galactose
PRIMARY SITE for carbohydrate metabolism is the
SMALL INTESTINE
Desirable intake of dietary fiber
25g-35g
○ Branched glucose polymer
○ Accounts for 80-85% of
the starch
Amylopectin
Monosaccharide unit: galactose, glucose, and fructose
RAFFINOSE
Monosaccharide units: galactose, glucose, fructose,
and an additional galactose
STACHYOSE
