Lecture 1 Exam — Notes

Levels of biological organization

Levels of biological organization

Biosphere, ecosystem, community, population, organism, organ, tissue, cell, organelle, molecule

Prokaryotic cell

No nucleus or membrane-enclosed organelles, usually very small

Eukaryotic

Membrane enclosed organelles, has a true nucleus

Chromosome

DNA & protein

Parts of a nucleotide

Phosphate, sugar, and a base

Domain eukarya

Plantae, fungi, animalia

Hypothesis

A testable explanation or observation

Experiment

Scientific test with controlled conditions

Element

Substance that cannot be broken down

Compound

Two or more elements

Atomic number

Sum of protons in the nucleus

Atomic mass

Sum of protons and neutrons in the nucleus

Valence electrons

Electrons in the outermost / valence shell

Covalent bond

Sharing of a pair of valence electrons

Electronegativity

Atoms attraction to electrons in a covalent bond

Nonpolar covalent bond

Atoms share the electron equally

Polar covalent bond

One atom is more electronegative

Ionic bond

Atoms strip electrons from bonding partners

Cation

Positively charged

Anion

Negatively charged

Water molecule

A polar molecule, form hydrogen bonds with EACH OTHER

Calorie

Amount of heat required to raise the temperature of 1g of water by 1 degree Celsius

Specific heat

How much heat must be absorbed/lost for 1g to change its temperature by 1 degree Celsius

Non-polar substances

lack polarity, therefore lack charges and do not dissolve in water

Solute

what is being dissolved

Solvent

dissolving agent

Acid

Increases the H+ concentration

Base

Decreases the H+ concentration (or increases the OH concentration)

Buffer

Minimize changes in concentrations of H+ / OH- in a solution

Organic compound

Compound with carbon

Elements frequently seen in life

C, H, O, N, S, and P

Functional groups

Components of organic molecules commonly involved in chemical reactions

Hydroxyl

-OH, alcohol

Carbonyl

-C=O, ketone / aldehyde

\

Carboxyl

C=OH

\

OH

Carboxylic acid. FOUND IN AMINO ACIDS.

Amino group

H

/

-N

\

H

Amine. FOUND IN AMINO ACIDS.

Sulfuhydryl group

-SH. Thiol

Phosphate

H

=

-O-P-O

|

O

Organic phosphate

Methyl

H

|

-C-H

|

H

Methylated compound