Exam 3 - module 8 Flashcards
What are the four classes of biomolecules?
Carbohydrates, Proteins, Lipids, Nucleic Acids
What are carbohydrates?
Polyhydroxylated macromolecules that are the main energy source for biological function.
What is the role of proteins?
Proteins are responsible for DNA replication, cell signaling, metabolic reactions, enzymatic reactions, and membrane transport.
What are lipids responsible for?
Lipids are responsible for membrane structure and energy storage.
What is the primary function of nucleic acids?
Nucleic acids are responsible for the storage and transfer of genetic information.
What is the key characteristic of carbohydrates in terms of oxygen?
Carbohydrates are highly oxygenated species that are a primary source of energy for the body.
What suffix is associated with sugars?
The suffix ‘-ose’ is used for sugars.
What is a monosaccharide?
A carbohydrate consisting of one sugar unit.
What is a disaccharide?
A carbohydrate consisting of two sugar units.
What is a polysaccharide?
A carbohydrate with multiple sugar units.
What are simple sugars?
Simple sugars have straight chains of sugars that are easily broken down.
What are complex sugars?
Complex sugars have branch chains that are more difficult to break down.
What is an aldose?
An aldose is a carbohydrate with an aldehyde group.
What is a ketose?
A ketose is a carbohydrate with a ketone group.
What is a triose?
A carbohydrate with three carbon atoms.
What is a tetrose?
A carbohydrate with four carbon atoms.
What is a pentose?
A carbohydrate with five carbon atoms.
What is a hexose?
A carbohydrate with six carbon atoms.
What is the D-sugar?
A natural sugar where the last hydroxyl group is on the right side.
What is an L-sugar?
A sugar where the last hydroxyl group is on the left side.
What is a Fischer projection of a carbohydrate?
The open-form of a sugar, with the carbon chain placed vertically.
What is a Haworth projection?
The closed-form of a sugar where the last hydroxyl group cyclizes onto the carbonyl group to form a ring.
What are diastereomers?
Stereoisomers that are not mirror images of each other.
What are enantiomers?
Stereoisomers that are mirror images of each other.
What is an alpha-anomer in sugar structures?
A cyclic sugar where the hydroxyl group is opposite to the CH2OH group.
What is a beta-anomer?
A cyclic sugar where the hydroxyl group is on the same side as the CH2OH group.
What is a glycosidic bond?
A bond linking two sugar units in a disaccharide.
What are common polysaccharides?
Chitin, cellulose, amylose, and amylopectin.
What functional groups do amino acids contain?
An amine functional group, a carboxylic acid functional group, and a side chain.
How are amino acids classified by side chain polarity?
Amino acids are classified as nonpolar (hydrocarbons), polar (alcohols, amides, thiols), or acidic/basic (carboxylic acids, amines).
What determines the isoelectric point (pI) of an amino acid?
The average of the pKa of the amine and carboxylic acid functional groups.
What happens when the pH is less than the pI of an amino acid?
The amino acid has a positive charge.
What happens when the pH is greater than the pI of an amino acid?
The amino acid has a negative charge.
What is the basic structure of an amino acid?
Typically drawn in bond-angle depiction or Fischer projection.
What is a peptide?
A chain of amino acids linked by peptide bonds.
What is a dipeptide?
A peptide consisting of two amino acids.
What is a tripeptide?
A peptide consisting of three amino acids.
What is a tetrapeptide?
A peptide consisting of four amino acids.
What is a polypeptide?
A long, continuous, unbranched chain of amino acids.
What are the N-terminus and C-terminus of a peptide?
The N-terminus is the beginning amine group, and the C-terminus is the ending carboxyl group.
What is a peptide bond?
An amide bond linking two amino acids.
Why are peptide bonds stable?
They are fairly unreactive and hinder rotation, leading to increased stability.
What is the primary structure of a protein?
The sequence of amino acids.
What stabilizes an alpha helix?
Intramolecular hydrogen bonding.
What stabilizes a beta sheet?
Intermolecular hydrogen bonding.
What defines the tertiary structure of a protein?
The unique three-dimensional shape formed by the folding of the protein backbone.
What interactions hold the tertiary structure of proteins together?
Ionic bonding, hydrogen bonding, disulfide linkages, and dispersion forces.
What is the quaternary structure of a protein?
The arrangement of multiple subunits into a larger protein structure.
What are the three main functional areas of lipids?
Energy storage, membrane structure, and chemical signaling.
What are the three main structural types of lipids?
Fatty acids, glycerides, and non-glycerides.
What is the structure of a fatty acid?
A 10–22 carbon tail group and a carboxylic acid head group.
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have no double bonds, while unsaturated fatty acids have double bonds.
What is an eicosanoid?
A hormone-like biomolecule synthesized from arachidonic acid.
What role do prostaglandins play in the body?
They are involved in inflammation, blood flow, blood clotting, and induction of labor.
What are leukotrienes involved in?
Allergic and inflammation responses.
What is the function of thromboxanes?
They are involved in blood platelet aggregation.
What are glycerides composed of?
A glycerol backbone with appended fatty acids.
What is the role of triglycerides in biological systems?
Energy storage and formation of lipid bilayers in membranes.
What are the types of glycerides?
Neutral glycerides (triglycerides) and ionic glycerides (phosphoglycerides).
What are sphingolipids?
Lipids enriched in the central nervous system involved in tissue development, cell recognition, and as toxin receptors.
What is the function of steroids?
Lipids responsible for signaling various biological functions.
What are waxes composed of?
Esters of fatty acids used as protective coatings.
What are complex lipids?
Lipids bonded to other types of molecules.
What are lipoproteins?
Complexes that carry lipids in the blood.
What are chylomicrons?
Lipoproteins that carry dietary triglycerides from the intestines to other tissues.
What is the role of VLDL?
It carries triglycerides from the liver.
What is the role of LDL?
It carries cholesterol to peripheral tissues.
What does HDL do in the body?
It carries cholesterol from peripheral tissues to the liver.
What are glycolipids?
Lipids containing a bound carbohydrate involved in cell membrane stability.
What is the primary role of nucleic acids?
Storage and transfer of genetic information.
What are the building blocks of nucleic acids?
Nucleotides.
What are the components of a nucleotide?
A heteroaromatic base, ribose sugar, and phosphate group.
What is the difference between DNA and RNA?
DNA stores genetic information, and RNA translates it into proteins.
What is transcription?
The process of creating RNA from a DNA template.
What is translation?
The process by which RNA directs protein synthesis.
