Unit 1 Review

Covalent Bonds

atoms share a pair of electrons. nonpolar shares equally, while polar shares unequally

ionic bonds

atoms transfer electrons to one another

hydrogen bonds

polar, weak interactions b/w two molecules that don’t involve electrons. important in creating cohesion in water, holding base pairs together in DNA, and stabilizing the secondary and tertiary structures of proteins

Cohesion and Adhesion

Water molecules stick to a plant's vascular tube (adhesion), pulling other water molecules up (cohesion), allowing plants to get water to leaves. 

Bonding Capacity

the number of electrons needed to fill the outer orbitals. Hydrogen can form 1, Carbon can form 4, oxygen can for 6, and nitrogen can form 3

Carbohydrates

crucial for short term energy, storage (starch in plants and glycogen in animals), and structural support (cellulose). Composed of C, H, and O

Dehydration synthesis

removing water to combine monomers in order to create a polymer

Hydrolysis

adding water to break down polymers in order to create monomers

Lipids

crucial for long term energy storage, making the cell membrane (phospholipids), and composing signaling molecules (steroids and hormones). Composed of C, H, and O

Fats

type of lipid used to store long term energy, insulate the body, and synthesize hormones

Saturated Fats

single bond, seen with a straight shape

Unsaturated Fats

double bonds, seen with a bent shape

Phospholipids

makes the cell membrane barrier, allowing for semi-permeability

Phospholipid head

hydrophilic

Phospholipid tails

hydrophobic

Steriods

hormones that act as chemical messengers and are used for communication to coordinate activities in the organism

Proteins

crucial for function and structure of enzymes, transporters and hormones. When denatured in the tertiary structure, it looses structure and function. Composed of C, H, O, and N

Nucleic Acids

responsible for storing, transmitting, and expressing DNA, guiding cell function and heredity. Composed of C, H, O, N, and P