The Structure and Function of Large Biological Molecules Flashcards

DNA
Terms Definitions
chitin
A structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeleton of all arthropods.
polypeptides
polymers of all amino acids
DNA
Deoxyribonucleic acid, the material that contains the information that determines inherited characteristics.
Amino Acids
Building blocks of proteins.
deoxyribonucleic acid
a double-stranded, helical nucleic acid molecule consisting of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine, guanine, cytosine, and thymine; it is capable of replicating and determining the inherited structure of a cell's proteins
nucleic acid
a polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins, and through the actions of proteins, for all cellular activities; two types are DNA and RNA
antiparallel
the pattern that describes the formation of DNA; the two sugar-phosphate backbones run in opposite 5' >> 3' directions from each other, somewhat like a divided highway
polysaccharide
A polymer of many monosaccharides, formed by dehydration reactions.
nucleic acids
A polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The two types are DNA and RNA.
Carbohydrates
Organic compounds made of carbon, hydrogen, and oxygen atoms in the proportion of 1:2:1.
Steroids
Lipids characterized by a carbon skeleton consisting of 4 fused rings.
Hydrolysis
The reverse of the dehydration reaction.
transport
the type of protein that transports other substances; example: hemoglobin, the iron-containing protein of vertebrate blood, transports oxygen from lungs to other parts of the body
hormonal
the type of protein that coordinates an organism's activities; example: insulin, a hormone secreted by the pancreas, helps regulate the concentration of sugar in the blood of vertebrates
Lipid
A hydrophobic molecule not made up glycerol and hydrocarbon chains that functions in energy storage and protection
fat
A lipid consisting of three fatty acids linked to one glycerol molecule; also called a triacylglycerol or triglyceride.
triacylglycerol
Three fatty acids linked to one glycerol molecule; also called a fat or a triglyceride.
enzyme
A macromolecule serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.
Cholesterol
A steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids.
monomers
repeating units that serve as building blocks of a polymer; smaller molecules; some also have functions on their own
polymer
a long molecule consisting of many similar or identical building blocks linked by covalent bonds, much as a train consists of a train of cars; carbohydrates, nucleic acids, and proteins are examples of these
macromolecules
giant molecules formed by the joining of smaller molecules, usually by a condensation reaction; polysaccharides, proteins, and nucleic acids are considered these
fats
made up of ester linkage, glycerol, and three fatty acids (palmitic acid)
messenger RNA
a nucleic acid that directs the production of polypeptides; this is found in the cells' ribosomes
trans fat
the fat that results when unsaturated fats are synthetically converted to saturated fats to prevent the separation of lipids (margarine and peanut butter are examples); this process produces saturated fats and unsaturated fats with trans double bonds
dehydration reaction
when two monomers connect to each other by a reaction in which a hydroxyl group covalently bonds to a hydrogen atom, which causes the loss of a water molecule in the process
sickle-cell disease
an inherited blood disorder that is caused by a substitution of one amino acid (valine) for the normal amino acid (glutamic acid) at a particular position in the primary structure of hemoglobin, the protein that carries oxygen in red blood cells
polypeptide
A polymer (chain) of many amino acids linked together by peptide bonds.
quaternary structure
The particular shape of a complex, aggregate protein, defined by the characteristic three-dimensional arrangement of its constituent subunits, each a polypeptide.
glycosidic linkage
A covalent bond formed between two monosaccharides by a dehydration reaction.
steroid
A type of lipid characterized by a carbon skeleton consisting of four rings with various chemical groups attached.
denaturation
In proteins, a process in which a protein unravels and loses it's native shape, thereby becoming biologically inactive; in DNA, the separation of the two strands of the double helix. Denaturation occurs under extreme (noncellular) conditions of pH, salt concentration, and temperature.
nucleotide
The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
Tertiary Structure
The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.
Unsaturated Fats
Plant products such as vegetable oil, nuts, and seeds, and in fish.
x-ray crystallography
the method used to determine 3-D structures of proteins; developed in 1959
deoxyribose
the sugar connected to DNA; has one less oxygen atom than the other sugar associated with nucleic acids
alpha helix
a secondary structure that is a delicate coil held together by hydrogen bonding between every fourth amino acid
macromolecule
a giant molecule formed by the joining of smaller molecules, usually by a condensation reaction
peptide bond
a covalent bond that results when two amino acids join through dehydration reaction
secondary structure
the collection of coils and folds that result from hydrogen bonds between repeating constituents of the polypeptide backbone (not the amino acid sides)
alpha (α) helix
A spiral shape constituting one form of the secondary structure of proteins arising from a specific pattern of hydrogen bonding.
ribonucleic acid
A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), Cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis, gene regulation, and as the genome of some viruses.
Fatty Acid
An organic acid that is contained in lipids, such as fats or oils.
receptor
the type of protein that helps a cell respond to chemical stimuli; example: receptors built into the membrane of a nerve cell detect chemical signals released by other nerve cells
beta pleated sheet
a secondary structure in which two or more regions of the polypeptide chain lying side by side are connected by hydrogen bonds between parts of two parallel polypeptide backbones; it makes up the core of globular proteins
β pleated sheet
Two or more regions of the polypeptide chain lying side by side are connected by hydrogen bonds between parts of the two parallel polypeptide backbones.
unsaturated fatty acid
a fatty acid that has one or more double-bonded carbon atoms formed by the removal of hydrogen atoms from the carbon skeleton; there will be a kink in the hydrocarbon chain wherever a -cis double-bond occurs (causes bending)
protein
A functional biological molecule consisting of one or more polypeptides folded and coiled into a specific three-dimensional structure.
disaccharide
molecule that consists of two monosaccharides joined by a glycosidic linkage
catalysts
chemical agents that selectively speed up chemical reactions without being consumed by the reaction; can be seen as workhorses that keep cells running by carrying out processes of life
gene
a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses)
starch
A storage polysaccharide in plants, consisting entirely of glucose monomers joined by glycosidic linkages.
cellulose
A structural polysaccharide of plant cell walls, consisting of glucose monomers joined by β glycosidic linkages.
Enzymes
Speed up chemical reactions in cells.
RNA
Ribonucleic acid, a natural polymer that is present in all living cells and that plays a role in protein synthesis.
enzymatic
the type of protein that selectively accelerates chemical reactions; example: digestive enzymes release polymers in food
Carbohydrate
A molecule made up of monosaccharides to form polysaccharides and that functions in energy storage (starch, glycogen) and structural support (cellulose, chitin)
monomer
The subunit that serves as the building block a polymer.
ribose sugar
sugar connected to the nitrogeneous base in the nucleotides of RNA
disulfide bridges
links that form where two cysteine monomers are brought together by folding of protein; covalent bonds reinforce structure
double helix
the shape that cellular DNA molecules take as a result of spiraling around an imaginary axis; this was proposed by James Watson and Francis Crick in 1953 at Cambridge University
unsaturated fat
a fat made from unsaturated fatty acids; they are liquid at room temperature (oils) because kinks in -cis bonding prevent molecules from packing together to solidify
pyrimidine
One of the two types of nitrogenous bases found in nucleotides, characterized by a six-membered ring. Cytosine (C), thymine (T), and uracil (U) are pyrimidines.
condensation reaction
A reaction in which two molecules become covalently bonded to each other through the loss of a small molecule, usually water, in which case it is also called a dehydration reaction.
ribose
the sugar connected to RNA; has one more oxygen atom than the other sugar associated with nucleicacids
structural
the type of protein that supports an organism; example: insects and spiders use silk fibers for cocoons and webs, collagen and elastin provide fibrous framework in animal connective tissues; keratin is protein of hair, horns, feathers, etc.
phospholipids
cells need these in order to exist because they make up cell membranes; has 2 fatty acids attached to glycerol instead of traditional 3 (triacylglycerol); always assemble into a double-layer aggregate because of hydrophilic head and hydrophobic tail
contractile and motor
the type of protein that controls movement; example: actin and myosin are responsible for the contraction of muscles; other proteins are responsible for the undulations of cilia and flagella
saturated fat
a fat made from saturated fatty acid; animal fats are solid at room temperature because they lack double-bonds, thus flexibility enables molecules to pack together tightly
saturated fatty acid
a fatty acid that has no double-bonded carbon atoms so that as many hydrogen atoms as possible are bonded to the carbon skeleton
unsaturated fatty acids
A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.
Saturated Fatty Acids
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton.
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