Bio 101- 1st Test

All living things-

- need nutrients

- process energy

- reproduce

- are made of cells

- have structure and order

- move/respond to environment

- grow and develop

Cell Theory

- Cells are the smallest form of life

- All cells come from other cells

Living things are organized

Molecules-> cells -> tissues -> organs -> organ system -> complex organisms

All living things use ___ as their genetic code

DNA

What is Science?

Science is a particular way we can understand the world.

Scientific method

Observations

Hypothesis

Predictions

Experiments

Theory

Qualitative data

Data that is descriptive i.e. photos.

Quantitative data

Data that is numerical i.e. graphs, # of people in class with...

Good quality experiments must

have independent and dependent variables.

have control groups.

have multiple replications.

Theory

an explanation of a phenomenon.

Law

usually refers to a generalization about data and is a compact way of describing what we'd expect to happen in a particular situation.

A law describes a phenomenom.

Molecules of Life

Atoms and Bonds

Element

Pure substance that couldn't be broken down further by methods of chemistry.

Elements essential to life

96% of living matter is made up of

- Carbon C

- Hydrogen H

- Oxygen O

- Nitrogen N

The remaining 4% of living matter is made up roughly of

- Phosphorus P

- Sulfur S

- Calcium Ca

- Potassium K

Atom

smallest unit of matter of a particular element.

Protons

Positively charged particles

Electrons

Negatively charged particles

Neutrons

Neutrally charged particles

The max # of electrons in the first orbital

2

Atomic # =

# of protons and electrons in an element

# of _____ never varies and gives atoms its identity

protons

The # of _____ can vary and determines the isotope.

neutrons

Referred to by mass #

isotopes

2 or more atoms

molecule

A substance that consists of 2 or more elements.

Compound

The outermost shell of an atom/

valence shell

Enable atoms to give up or acquire electrons to complete their valence shell.

chemical reactions

Primary Bonds

Covalent and Ionic

Secondary Bonds

Hydrogen

Covalent Bonds

occur when 2 atomic orbitals each containing 1 electron merge into a single orbital.

Non-Polar Covalent Bonds

atoms share electrons equally.

Polar Covalent Bonds

an atom pulls electrons more strongly towards themselves because they are more electronegative.

Ionic Bonds

start when 1 atom steals an electron from another atom.

happen when 2 ions of opposite charge come together.

Hydrogen Bonds

interaction between a hydrogen atom with a slight positive charge and an electronegative atom of another molecule.

Cohesion

water molecules tend to stick to one another giving it high surface tension.

Adhesion

water molecules tend to stick to other surfaces.

Temperature Stability

water molecules tend to stick to one another giving it high surface tension.

Less Dense Ice

Water molecules are held apart, so ice is less dense and take up larger volume than liquid water.

H-bonds hold the water molecules apart in a crystalline structure that makes it less dense than liquid water.

Solvent

able to absorb other substances

H+>OH-

Acidic (lower pH)

H+

Basic (higher pH)

Large molecules are made up of repeating units called ___

Monomers

Monomers connect to form...

Polymers

Polymers are broken down to form...

Monomers

Carbohydrates/Polysaccharides

- monomer: monosaccharide

- sweet taste

- water soluble due to all the -OH groups

- "-ose" indicates a sugar

Complex Carbohydrates/Polysaccharides

- straight or branched chain of hundreds or thousands of monomers

- i.e. starch, glycogen, cellulose, chitin