AP®︎ Biology: Unit 1 Flashcards

Weak attraction between a partially positive hydrogen and a nearby electronegative atom.

Attraction between water molecules caused by hydrogen bonds.

Attraction between water molecules and other polar or charged substances.

Resistance of a liquid surface to breaking, caused by strong cohesion among surface molecules.

Evaporation removes the highest-energy molecules, lowering the temperature of the remaining liquid.

Hydrophilic substances interact with water; hydrophobic substances are nonpolar and avoid mixing with water.

Its polarity allows it to surround and dissolve many ionic and polar substances.

Unequal electron sharing in O-H bonds gives oxygen a partial negative charge and hydrogens partial positive charges.

It resists temperature change because much energy is needed to disrupt hydrogen bonds.

A large amount of energy is required for evaporation because many hydrogen bonds must break.

Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur are the six key elements of life.

These are the most prevalent elements in carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrates: CHO; proteins: CHONS; lipids: mostly CHO, phospholipids include P; nucleic acids: CHONP.

Carbon has four valence electrons and can form four covalent bonds.

A chain or ring of bonded carbon atoms that forms an organic molecule's framework.

Nitrogen is found in amino groups and is required in proteins and nucleic acids.

Phosphorus is part of phosphate groups in nucleic acids and phospholipids.

Sulfur occurs in some amino acids and is used in building proteins.

Specific atom groups attached to carbon skeletons that determine molecular properties and include hydroxyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl.

Joins monomers by removing H and OH to form water and a covalent bond.

Breaks covalent bonds by adding water, splitting polymers into smaller molecules or monomers.

A chemical bond formed when atoms share one or more pairs of electrons.

A molecule's shape and bonding pattern determine what it can do in cells.

Small subunits covalently join to form large molecules through repeated bonding reactions.

Single sugar units that act as monomers for larger carbohydrate molecules.

Long chains of monosaccharides linked by covalent bonds, forming linear or branched polymers.

A covalent bond that joins monosaccharides together in carbohydrates.

Some sugar polymers form straight chains, while others have side branches off the main chain.

A plant storage polysaccharide made of glucose monomers.

A highly branched glucose storage polysaccharide found in animals and fungi.

A structural polysaccharide in plant cell walls made of glucose monomers.

Organic molecules of sugars and sugar polymers used for energy storage and structural support.

Saturated have only single bonds; unsaturated have one or more double bonds that create kinks.

More double bonds increase kinks and make a lipid more liquid at room temperature.

Energy-storing lipids that can also provide insulation, cushioning, and support for cell function.

Amphipathic lipids with hydrophilic heads and hydrophobic tails that form membranes.

Having both a hydrophilic region and a hydrophobic region in the same molecule.

A double layer of phospholipids with tails inward and heads facing watery environments.

Lipids with four fused carbon rings, often functioning as hormones in regulation.

A steroid in animal membranes that stabilizes structure and helps regulate fluidity.

The arrangement of fatty acids and other parts determines a lipid's properties and roles.

Mostly nonpolar, hydrophobic molecules such as fats, phospholipids, and steroids that function in energy storage, membranes, and signaling; unlike many other macromolecules, they usually are not true polymers.

A monomer made of a five-carbon sugar, phosphate group, and nitrogenous base.

DNA usually has deoxyribose, thymine, and two strands; RNA usually has ribose, uracil, and one strand.

Adenine, guanine, cytosine, thymine, and uracil are the base components of nucleotides.

Purines are adenine and guanine; pyrimidines are cytosine, thymine, and uracil.

Alternating sugars and phosphates form the covalently bonded outer framework of a nucleic acid strand.

Strand direction is defined by a 5' phosphate end and a 3' hydroxyl end.

Adjacent nucleotides are joined by covalent bonds when new nucleotides are added to the 3' end.

Two DNA strands run in opposite 5' to 3' directions and twist around each other.

A pairs with T in DNA or U in RNA, and C pairs with G.

A-T and A-U form two hydrogen bonds, while C-G forms three hydrogen bonds.

In double-stranded DNA, the amount of adenine equals thymine and guanine equals cytosine.

A DNA sequence that contains instructions for making a specific protein or functional product.

mRNA carries coding information, tRNA brings amino acids, and rRNA forms part of ribosomes.

DNA stores hereditary information, while RNA helps transmit and express that information.

Nucleic acids are polymers of nucleotide monomers that form DNA or RNA and store and transmit hereditary information.

A central carbon bonded to an amino group, carboxyl group, hydrogen, and variable R group.

Nonpolar hydrophobic, polar hydrophilic, and ionic charged side chains with different chemical behaviors.

The specific linear sequence of amino acids in a polypeptide.

Local folding of the polypeptide backbone into alpha helices and beta pleated sheets by hydrogen bonding.

The overall three-dimensional shape of one polypeptide formed by side-chain interactions.

Hydrogen bonds, ionic interactions, hydrophobic interactions, and disulfide bridges stabilize one polypeptide's shape.

The association of multiple polypeptide subunits into one functional protein.

Common roles include catalysis, structure, transport, signaling, defense, and movement.

A covalent bond between sulfur-containing side chains that stabilizes a protein's folded shape.

Proteins are polymers of amino acids; amino acid monomers are linked by covalent peptide bonds to form linear polypeptide chains that fold into functional proteins.