DAT- Chapter 1: Molecules and Fundamentals of Biology

anything that takes up space and has mass.

a pure substance that has specific physical/chemical properties and can’t be broken down into a simpler substance

the smallest unit of matter that still retains the chemical properties of the element

two or more atoms joined together

attractive forces that act on atoms within a molecule.

forces that exist between molecules and affect physical properties of the substance.

single molecules that can potentially polymerize.

substances made up of many monomers joined together in chains.

contain carbon, hydrogen, and oxygen atoms

are carbohydrate monomers with an empirical formula of (CH2 O)n . “n” represents the number of carbons.

same chemical formula, different arrangement of atoms

glycosidic bond

where a water molecule leaves and a covalent bond forms.

a covalent bond is broken by the addition of water.

disaccharide made of glucose + fructose

disaccharide made of galactose + glucose

disaccharide made of glucose + glucose.

contain multiple monosaccharides connected by glycosidic bonds to form long polymers.

form of energy storage for plants and is an alpha (α) bonded polysaccharide.

Linear starch

the branched form of starch

form of energy storage in animals and is an alpha (α) bonded polysaccharide. It has much more branching than starch

structural component in plant cell walls, and is a beta (β) bonded polysaccharide. Linear strands packed rigidly in parallel

structural component in fungi cell walls and insect exoskeletons. It is a beta (β) bonded polysaccharide with nitrogen added to each monomer.

1. carbon, hydrogen, oxygen, and nitrogen atoms (CHON)

2. amino acids

3. polypeptides (or proteins)

all the proteins expressed by one type of cell under one set of conditions.

are the monomers of proteins

Amino group (NH3), Hydrogen, Carboxyl group (O-C=O), and R-group connected to a central Carbon

polymers of amino acids

peptide bonds

through dehydration (condensation) reactions

N-terminus (amino terminus)

C-terminus (carboxyl terminus)

ends with the last amino acid’s amino group.

ends with the last amino acid’s carboxyl group.

proteins that are composed of amino acids and non-protein components

Metalloproteins (ex. hemoglobin)

Glycoprotein (ex. mucin)

proteins that contain a metal ion cofactor.

proteins that contain a carbohydrate group.

1. Primary structure

2. Secondary structure

3. Tertiary structure

4. Quaternary structure

sequence of amino acids connected through peptide bonds.

intermolecular forces between the polypeptide backbone (not R-groups) due to hydrogen bonding. Forms α-helices or β-pleated sheets

three-dimensional structure due to interactions between R-groups. Can create hydrophobic interactions based on the R-groups. Disulfide bonds are created by covalent bonding between the R-groups of two cysteine amino acids. Hydrogen bonding and ionic bonding between R groups also hold together the tertiary structure.

multiple polypeptide chains come together to form one protein

the loss of protein function and higher order structures. Only the primary structure is unaffected.

high or low temperatures, pH changes, and salt concentrations

Storage = Reserve of amino acids

Hormones = Signaling molecules that regulate physiological processes

Receptors = Proteins in cell membranes which bind to signal molecules

Structure = Provide strength and support to tissues (hair, spider silk)

Immunity = Antibodies that protect against foreign substances

Enzymes = Regulate rate of chemical reactions

increase reaction rates

by lowering activation energy of a reaction

the unstable conformation between the reactants and the products.

the transition state.

shift a chemical reaction or affect spontaneity.

binding to substrates (reactants) and converting them into products.

Where enzymes bind to substrates and is specific for the substrate that it acts upon

proteins

how efficient an enzyme is at binding to the substrate and converting it to a product

how the active site molds itself and changes shape to fit the substrate when it binds. The “lock and key” model is an outdated theory of how substrates bind.

an RNA molecule that can act as an enzyme (a non-protein enzyme).

is a non-protein molecule that helps enzymes perform reactions

an organic cofactor (i.e. vitamins). Inorganic cofactors are usually metal ions

are enzymes that are bound to their cofactors

are enzymes that are not bound to their cofactors.

are cofactors that are tightly or covalently bonded to their enzymes.

● Conformational changes that bring reactive groups closer.

● The presence of acidic or basic groups.

● Induced fit of the enzyme-substrate complex.

● Electrostatic attractions between the enzyme and substrate.

Cleaves a phosphate group off of a substrate molecule

Directly adds a phosphate group to a substrate molecule by breaking bonds within a substrate molecule

Indirectly adds a phosphate group to a substrate molecule by transferring a phosphate group from an ATP molecule. These enzymes do not break bonds to add the phosphate group.

the end product of an enzyme-catalyzed reaction inhibits the enzyme’s activity by binding to an allosteric site.

an inhibitor competes directly with the substrate for active site binding. Adding more substrate can increase enzyme action.

the noncompetitive inhibitor binds to an allosteric site (a location on an enzyme that is different from the active site) that modifies the active site. In noncompetitive inhibition, the rate of enzyme action cannot be increased by adding more substrate.

the maximum reaction velocity

is the substrate concentration [X] at which the velocity (V) is 50% of the maximum reaction velocity (Vmax).

all active sites are occupied, so the rate of reaction does not increase anymore despite increasing substrate concentration (causes graph plateaus).

Km increases

stays the same

KM stays the same,

while Vmax decreases

carbon, hydrogen, and oxygen atoms (CHO), like carbohydrates

make them very hydrophobic.

a glycerol backbone (three carbons and three hydroxyl groups)

and three fatty acids (long hydrocarbon tails).

ester linkages

have double bonds.

have NO double bonds and as a result pack tightly (solid at room temperature).

monounsaturated fatty acids have 1 double bond while polyunsaturated fatty acids have have 2 or more double bonds.

Cis-unsaturated fatty acids have kinks that cause the hydrocarbon tails to bend. As a result, they do not pack tightly.

Trans-unsaturated fatty acids have straighter hydrocarbon tails, so they pack tightly.

glycerol backbone, one phosphate group, and two fatty acid tails

amphipathic (both hydrophobic and hydrophilic)

steroid hormones (lipids with four hydrocarbon rings)

vitamin D and bile acids

Temperature - ↑ temperatures increase fluidity while ↓ temperatures decrease it.

Cholesterol - holds membrane together at high temperatures and keeps membrane fluid at low temperatures. (acts kind of as a buffer to counteract temp)

Degrees of unsaturation - saturated fatty acids pack more tightly than unsaturated fatty acids, which have double bonds that may introduce kinks

allow the transport of lipid molecules in the bloodstream due to an outer coat of phospholipids, cholesterol, and proteins.

can cause vessel blockage and heart disease.

have low protein density and work to deliver cholesterol to peripheral tissues.

have high protein density and take cholesterol away from peripheral tissues

they deliver cholesterol to the liver to make bile (reduces blood lipid levels).

Waxes which are simple lipids with long fatty acid chains connected to monohydroxy alcohols (contain a single hydroxyl group) through ester linkages

lipid derivatives containing long carbon chains with conjugated double bonds and six-membered rings at each end. They function mainly as pigments.

have a backbone with aliphatic (non-aromatic) amino alcohols and have important functions in structural support, signal transduction, and cell recognition.

are lipids found in the cell membrane with a carbohydrate group attached instead of a phosphate group in phospholipids. Like phospholipids, they are amphipathic and contain a polar head and a fatty acid chain.

carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms (CHONP)

nucleotide monomers that build into DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) polymers

contain a five-carbon sugar and a nitrogenous base.

contain a five-carbon sugar, a nitrogenous base, and a phosphate group.