NATURE OF LIFE

LIVING ORGANISMSComposition and structure

Composed of tiny structural units Cells

Cells around bound by a semi-permeable living membrane Plasma membrane

Cells are rigid due to outer structure Cell wall

Cells communicate with each other through microscopic tunnels Plasmodesmata

LIVING ORGANISMSComposition and structure

Cells contain soupy liquid Cytoplasm

Cells contain genetic material to control activities and development DNA

DNA is housed inside a special structure floating in cytoplasm Nucleus

LIVING ORGANISMSGrowth

Increase in mass

LIVING ORGANISMSReproduction

Offspring resembles parents

Genetic variations drive evolution Natural selection

Environment favors certain characteristics

LIVING ORGANISMSResponse to stimuli

Interaction with environment

Plants respond to injury Production of callose Seal wound

LIVING ORGANISMSMetabolism

Biochemical reactions inside an organism Growth Repair damage Cell maintenance

Energy-releasing production (consumption) Respiration

Energy-production and storage process Photosynthesis

LIVING ORGANISMSMovement

Reactions to environment Leaves closing Cytoplasmic streaming inside cell Sunflowers turning

ELEMENTS OF MATTER Stuff of the universe

Occupies space Mass Composed of elements

Atoms Subatomic particles

Quarks Gluons Higgs boson

LARGE HADRON COLLIDER (LHC) 

ATOM Nucleus contains two particles

Protons Positively charged particles

Neutrons No electrical charge

ATOM Electrons

Negatively charge particles Orit the nucleus

Same amount of electrons as protons Atom has no charge

(neutral)

ELEMENTS The number of protons and

neutrons determine the element Hydrogen (H)

1 proton Part of nearly all life

Carbon (C) 6 protons Skeleton of molecules

MOLECULES 2 or more atoms attached to each other

Molecule Random collisions of atoms Chemical reactions between atoms

MOLECULES Water

2 Hydrogen (H) 1 Oxygen (O)

Slight negative charge on one side, slight positive charge on other side Polar molecule

MOLECULES Water molecules polarity is reason for

cohesion and adhesion Hydrogen bonding

Attraction to each other (cohesion) Surface tension

Attraction to other negatively charge particles (adhesion) fibers

BONDS Covalent bonds

Atoms share electron

Ionic bonds One atom donates an electron to another atom The result are ions

Positively or negatively charged atoms

BONDS Ion

Number of electron does not equal protons Atom is negatively or positively charged

Ionic bonds +ion attracted –ion

BONDS Hydrogen bonds

Weak attraction of polarity

ACIDS AND BASES Acid solution

Surplus of hydrogen (H) ion (+)

Basic solution Surplus of hydroxyl (OH) ions

(-)

PH SCALE 0 to 14

7 pH is neutral

<7 pH Acidic

>7 pH Basic