living things

Characteristics of living organisms:

(Seven of them)

- consist of one or more cells

- contain genetic information

- genetically related and have evolved

- can convert molecules from their environment into new biological molecules

- can extract energy from the environment and use it for biological work

- can regulate their internal environment

Evolution

a central theme: living systems evolve through differential survival and reproduction

unicelluar

multicellular

made of many cells that are specialized for different functions

Cell Theory:

(Six points)

- cells are the basic structural and physiological units of life

- cells are both distinct entities and building blocks of more complex organisms

- all cells come from pre-existing cells

- all cells are similar in chemical comp. 

- most of the chemical reactions of life occur within cells

- complete sets of genetic info. are replicated and passed during cell division

Schleiden and Schwann

adaption

deoxyribose nucleic acid: genetic info. passed from parent to daughter cells

sum total of all DNA in a cell

- all cells in multicellular organisms have the same genome unless an abnormality occurs

a specific segment of DNA

- contains info. to make proteins

- mutations occur in the sequence

Life chain:

(11 steps)

single-celled organisms

- located in oceans, protected from UV radiation

formation of a carbohydrate using sunlight, water, and CO2

- led to formation of ozone layer and O2 in atmosphere

the naming process:

Genus species

Homo sapien

Scientific Method:

( 5 Steps)

- Observations

- Questions

- Hypothesis

- Predictions

- Experimentation

inductive logic

unstable and give off energy in the form of radiation from the nucleus 

- decay transforms atoms

describe location of electrons in atom

- where the electron is 90% of the time

where orbitals occur in series

- also known as energy levels

atoms share one or more pairs of electrons

- very strong bond

two atoms have similar electronegativity

- electrons shared equally

polar covalent bond

one atom has more electronegativity 

- electrons drawn to nucleus

- not shared equally

attractions between non-polar molecules

- individual interactions are brief and weak but add up to a substantial amount

atoms bond or change bonding partners

- matter is neither created nor destroyed

capacity to do work

- usually changes form during chemical reactions

unique structure and special properties 

- polar molecule that forms hydrogen bonds

water molecules resist coming apart from one another

- helps water move through plants

- results in surface tension

amount of a substance (in grams); the mass of which is numerically equal to its molecular weight

- 6.02 x 10^23 molecules

negative log of the molar concentration of H+ ions

- the lower the pH, the more acidic the solution

a weak acid and its corresponding base

- helps maintain pH

-proteins

- nucleic acids

- carbohydrates

- lipids

- structural support

- regulation

- movement

- defense

- catalyst

- protection

- transport

what make up proteins

- essential amino acids: what the body can't produce on its own

- 20 total amino acids

[image]

covalently bonded amino acids together

- forms polypeptide chain

sequence of amino acids in a protein

- determines secondary structure and tertiary structure (how it folds)

Helix: right-handed coil from hydrogen bonding

Pleated Sheet: two or more polypeptide chains are aligned

bending and folding results in a macromolecule with a specific 3D shape

- affected by high temps., pH changes, and high concentrations of polar molecules

molecules in which carbon is flanked by hydrogen and hydroxyl groups

H--C--OH

Functions of carbs:

(two)

- energy source

- carbon skeletons for many other molecules

hundreds of monosaccharides 

- starch, glycogen

monosaccharide; used by cells as energy source 

- usually exists as a strong ring

nonpolar hydrocarbons

* serve as insulation in animals, repel water, prevent drying

- fats and oils: energy storage

- phospholipids: cell membranes

- cartenoids

 - steroids

simple lipids

- made of 3 fatty acids and 1 glycerol

no double bonds between carbons; saturated with hydrogen atoms

- typically animals fat, packed tightly, solid at room temp.

some double bonds with carbons

- typically plant oils, kinks prevent packing, liquid at room temp.

fatty acids bound together to glycerol, a phosphate group replaces one fatty acid 

- phosphate group is hydrophylic and polar

[image]

DNA: deoxyribose nucleic acid

RNA: ribose nucleic acid

- consist of a pentose sugar (5 carbon), a phosphate group, and a nitrogen-containing base

[image]

adenine -- thymine

guanine -- cytosine

- uracil replaces thymine in RNA

- purines pair w/ pyrimidines by hydrogen bonding

- folded RNA can act as a catalyst- ribozyme