Chapter 2

solvent

A liquid substance capable of dissolving other substances

Polysaccharides

A long chain of monosaccharides linked by covalent bonds (poly- = "many").

Polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds. (Used interchangeably with proteins)

cellulose

A substance (made of sugars) that is common in the cell walls of many organisms

Which property/properties contributes to the high surface tension of water? A hydrogen bonding B polar covalent bonds C cohesion D polar covalent bonds and cohesion E All of the choices are correct.

E

protein secondary structure

Folding patterns resulting from interactions between the non-R group portions of amino acids give rise to the secondary structure of the protein. The most common are the alpha (α)-helix and beta (β)-pleated sheet structures

cohesion

shape of the dew droplets

Disaccharide

(di=2) A double sugar, consisting of two monosaccharides joined by dehydration synthesis. Common disaccharides include lactose, maltose, and sucrose

atomic weight number

(just below chemical symbol). This number represents average mass of the specific element

radioactive isotopes

isotopes are unstable and will loose protons, other subatomic particles, or energy to form more stable elements

chitin

Polysaccharide found in arthropod exoskeletons and fungal cell walls.

Which one of these statements are true about carbohydrates?

Proportion of C:H:O in monosaccharides is 1:2:1

amino acids

building blocks of proteins. The R group is the only difference in structure between the 20 amino acids; otherwise, the amino acids are identical

adhesion

dew drop "sitting" on the leaf without rolling off

electron

is a negatively charged particle that travels in the space around the nucleus.

four major classes of biological macromolecules

1. carbohydrates, 2. proteins, 3. nucleic acids, and 4. lipids

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Which one of these is true about amino acids? (choose all that apply)

Amino acids differ from each other based on R-group structure

atom

An atom is the smallest component of an element that retains all of the chemical properties of that element.

cohesion

Attraction between molecules of the same substance

Which one of these is NOT true about nucleic acids? (choose all that apply) A they are made of monomers called nucleotides B nucleotides are made of 3 parts: nitrogenous base, sugar, and phosphate group C nucleotides are connected to each other in a chain by connecting phosphate of one to sugar of the next nucleotide D In DNA, nitrogenous bases of 2 chance face each other and connect via covalent bonds making "ladder-like" structure

D

lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen. Hydrophobic ("water-fearing"), or insoluble in water, because they are nonpolar molecules.

acidity

Pure water is neutral. It is neither acidic nor basic, and has a pH of 7.0. Anything below 7.0 (ranging from 0.0 to 6.9) is acidic, and anything above 7.0 (from 7.1 to 14.0) is alkaline.

nucleotides

building blocks of nucleic acids that make up DNA and RNA Each nucleotide is made up of three components: 1. a nitrogenous base, 2. a pentose (five-carbon) sugar, and 3. a phosphate group

non polar covalent bond

equal sharing of electrons

ionic bond

formed between 2 or more atoms with extremely large difference in electronegativity resulting in one atom taking completely electrons from the other electron (bond is between 2 charged particles)

polar covalent bond

formed between 2 or more atoms with large difference in electronegativity and is marked by unequal sharing of the electrons where part of the newly formed molecule has section with partly negative charge and section with partly positive charge

fructose (isomers) (monosaccharides)

fruit sugar

temperature

is a measure of the motion (kinetic energy) of molecules

neutrons

like protons, reside in the nucleus of an atom. They have a mass of 1 and no charge.

protein primary structure

linear sequence of amino acids

when an atom loses an electron, it becomes a ___________ ion

positively

proton

positively charged particle that resides in the nucleus (the core of the atom) of an atom and has a mass of 1 and a charge of +1

Which one of these is NOT true about proteins

protein and polypeptide are interchangeable terms

monomers

small unit that can join together with other small units to form polymers

glycogen

storage form of glucose in humans and other vertebrates, and is made up of monomers of glucose

starch

stored form of sugars in plants and is made up of amylose and amylopectin (both polymers of glucose)

Using a pH meter, you find the pH of an unknown solution to be 2.5. How would you describe this solution?

strongly acidic

hydrogen bond

weak bond between molecules with polar covalent bonds where partially negatively charged area of one molecule is attracted by partially positively charged area of another molecule

nucleic acids

Nucleic acids are key macromolecules in the continuity of life. They carry the genetic blueprint of a cell and carry instructions for the functioning of the cell.

proteins

Nutrients the body uses to build and maintain its cells and tissues polymers of amino acids. All proteins are made up of different arrangements of the same 20 kinds of amino acids.

cohesion and surface tension

pain when you belly flop into pool

carbohydrates

ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules. Carbohydrates are classified into three subtypes: monosaccharides, disaccharides, and polysaccharides.

Using a pH meter, you find the pH of an unknown solution to be 12.0. How would you describe this solution?

strongly basic

acids

substances that release hydrogen ions when dissolved in water

surface tension

the force that acts on the surface of a liquid and that tends to minimize the area of the surface

protein quaternary structure

the number and arrangement of multiple folded protein subunits in a multi-subunit complex

Monosaccharides

(mono- = "one"; sacchar- = "sweet") are simple sugars, the most common of which is glucose Monosaccharides are monomers of disaccharides and polysaccharides. Monosaccharides may exist as a linear chain or as ring-shaped molecules; in aqueous solutions, they are usually found in the ring form.

Which one of these is NOT correct regarding lipids? (choose all that apply) A Lipids are made of monomers B Triglycerides are made of glycerine connected to 3 fatty acids C Phospholipids are made of glycerine, 2 fatty acids, and phosphate group D Steroids are made of glycerine and 4 fatty acids E Waxes are special types of lipids F Saturated fats are good for you

A

dna

A complex molecule containing the genetic information that makes up the chromosomes.

polar covalent bond

A covalent bond in which electrons are not shared equally

isotopes

Atoms of the same element that have different numbers of neutrons

ionic bonds

Formed when one or more electrons are transferred from one atom to another

Biological Macromolecules

The large molecules necessary for life that are built from smaller organic molecules

protein tertiary structure

Three-dimensional shape formed by interactions between R groups. Caused by chemical interactions between various amino acids and regions of the polypeptide

hydrogen bonds

Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule. Hydrogen bonds can form between different molecules and they do not always have to include a water molecule. Hydrogen atoms in polar bonds within any molecule can form bonds with other adjacent molecules

ion

When an atom does not contain equal numbers of protons and electrons

triglycerides

an energy-rich compound made up of a single molecule of glycerol and three molecules of fatty acid.

non polar covalent bond

formed between 2 or more atoms with small difference in electronegativity and is marked by equal sharing of the electrons

carbon bonding

four electrons in its outer shell. Therefore, it can form four covalent bonds with other atoms or molecules.

Sucrose (table sugar) (disaccharide)

glucose + fructose

Lactose (milk sugar) (disaccharide)

glucose + galactose

Maltose (malt sugar) (disaccharide)

glucose + glucose

galactose (isomers) (monosaccharides)

milk sugar

buffers

mixtures that can react with acids or bases to keep the pH within a particular range

polymers

molecules composed of many monomers; makes up macromolecules

rna

mostly involved in protein synthesis. The DNA molecules never leave the nucleus, but instead use an RNA intermediary to communicate with the rest of the cell

electron transfer

movement of electrons from one element to another

cohesion and adhesion

movement of water from roots to the leafs

When an atom gains an electron it becomes

negatively charged