Basic Macromolecules in a Biological System

What is an element?

pure substance that cannot be broken into simpler substances

What are monomers?

Molecules that can bond to similar molecules to form a polymer

What is a polymer?

A substance composed of similar units bonded together ^{(large molecule with multiple monomers linked)}

What is a dehydration reaction? (what occurs, what type of bond forms, does it require energy, what does it build) (4)

Releases a water molecule and forms a covalent bond between two monomers; requires energy; builds polymers

What is a hydrolysis reaction? What is the relationship to energy?

Water cleaves a covalent bond into two products; breaks polymers into monomers; releases energy

What are macromolecules? What are the four major types?

Large polymers built from monomers; carbohydrates, lipids, proteins, and nucleic acids

What is the general formula for a carbohydrate monomer? (use n for variable)

CnH₂nOn

What is a monosaccharide?

A simple sugar (basic building block for carbohydrates)

What is a disaccharide? How did it become this from a monosaccharide?

Two monosaccharides joined by dehydration synthesis (ex: sucrose = glucose + fructose)

What are polysaccharides?

Carbohydrate polymers made of many linked sugar molecules

What is glycogen, what does it store? Where can you find it (2)? What is it’s use?

The polysaccharide animals use to store glucose; stored in liver/muscles; hydrolyzed back into glucose for energy

What is starch? (who uses this and what is the function)

The polysaccharide plants use to store carbohydrates

What are oligosaccharides? Where are they found? What is it’s function?

Carbs with a small number of monosaccharides; found on the cell membrane surface; function in cell recognition

What is cellulose? Who uses it?

A structural carbohydrate; plant cell walls are made from this

What is chitin?

A linear, structural carbohydrate ^{(a tough, natural sugar polymer that forms the hard outer shells of insects and crustaceans, as well as the cell walls of fungi)}

What are glycoproteins/glycolipids? What is the function?

Molecules combining carbohydrates with proteins/lipids; function in cell recognition

What is glycerol? (2)

A sugar compound that serves as the backbone for triglycerides and phospholipids

What does hydrophobic mean?

Water fearing

What is a fatty acid? (describe it)

A long hydrocarbon chain with a carboxylic acid group on one end

What are lipids? What is the functions (3)?

fatty-acid chains attached to glycerol; function in structure, energy storage, hormones

Are lipids true polymers?

no ^{(they don’t consist of repeating monomer units)}

Are lipids non-polar or polar and are they hydrophillic or hydrophobic?

non-polar; hydrophobic

What are the 4 types of lipids?

Fats/oils, waxes, phospholipids, steroids (all insoluble in water)

What is the molecular composition of a fat (2)? What are the functions (3)?

Glycerol backbone + 3 fatty acid chains; energy storage, cushioning, insulation

What is the molecular composition of a wax (2)? Is it hydrophobic or hydrophillic? What is the function?

Long fatty acid chains + alcohols; hydrophobic; keeps organisms dry (feathers, leaves)

What is the molecuar composition of a phospholipid (2)? What does it form?

2 fatty acid chains + a phosphate molecule; forms the semipermeable cell membrane

What is the molecular structure of a steroid? What does it do?

Four-ring lipid structure (ex: cholesterol, sex hormones); acts as chemical messengers

What are proteins made of?

Polymers of amino acid monomers

What makes up an amino acid? (4)

A central carbon, amine group, carboxylic acid, and variable R side chain

How many amino acids are there?

20 (differing by their R side group)

Basic amino acids have ______ R side chains

positive (+)

Acidic amino acids have _____ R side chains

negative (-)

What is a peptide bond?

The covalent bond linking amino acids together in a protein

Are fibrous proteins hydrophobic or hydrophilic, and what is their function?

Hydrophobic; structural ^{(ex: keratin in hair, collagen in nails)}

Are globular proteins hydrophobic or hydrophillic? What are the 3 functions?

Hydrophilic; function as carriers (hemoglobin), antibodies, enzymes

What is a membrane protein? What is its function (2)?

Amphipathic amino acids; functions in transport/signaling

What is an enzyme? It speeds up reactions without being _______. What does it essentially do (via reaction)?

A protein catalyst; consumed; lowers the energy needed to start the reaction

What is an active site?

location on enzyme where substrate binds

What is an exergonic reaction?

A reaction that releases energy

What is an endergonic reaction?

A reaction that requires energy input

What is ATP (Adenosine triphosphate)?

molecule that supplies usable energy in cells

What is pepsin? (where is it from, what does it start?)

enzyme from stomach cells; starts protein digestion

What are nucleic acids? What elements do they contain (5)

Polymers of nucleotides; Hydrogen, Carbon, Oxygen, Nitrogen, and Phosphorus

What are the 3 parts of a nucleotide?

A nitrogenous base, a sugar, and a phosphate group

What is a phosphate group?

A phosphorus atom bound to four oxygen atoms

What are the two nucleic acids in living things?

DNA and RNA

What is DNA?

Double-stranded helix storing genetic info

What is a gene?

A DNA segment coding for a protein ^{(can be a few hundred to over a million bases long)}

What are chromosomes made of (2)? Where are they located within a cell? What is located here?

DNA and protein; nucleus; genes

What is ribonucleic acid (RNA)? What does it do?

macromolecule (present in all cells) that controls the intermediate steps for protein synthesis

What is RNA's structure?

single stranded

What is mRNA?

Transcribes the genetic code from DNA , carries it to the ribosome

What is rRNA? (location and function)

Located in ribosomes; helps build proteins

What is tRNA?

Brings the amino acid coded by mRNA to the ribosome

What is a ribosome?

Site of protein synthesis ^{(provides the catalytic environment for peptide bonds to form)}

What is the genetic code?

The set of 64 codons that specify the 20 amino acids

What is a mutation?

An error in nucleotide sequence that (typically) disrupts protein structure/function