Debate between spontaneous generation and biogenesis

Redi

• performed the first biological experement

• jars open with meat and jars closed with meat

• the open jars had maggots and flies while the closed jars had nothing

• believed in biogenesis (maggots and flies came from fly eggs)

Louis Pasteur

designed an s-shaped flask and boiled the meat broth in the flask. The micro organisms got caught in the “S”, therefore, the broth remained clear

Debate is over, life comes from life, these experiments have caused a paradigm shift, changing the way we think.

Cell theory

The cell theory is one of the basic principles of biology

• all living organisms are composed of one or more cells

• cells are the most basic units of structure and function in all organisms

• all cells are derived from pre-existing cells

• in a multicellular organism, the activity of the organism depends upon the total activity of its independant cells

The development of microscopy contributed to the cell theory by allowing people to see cells more in depth, which lead to a further understanding and study of the cells

Chemical reactions are always occuring in our cells, ex. our cells are currently breaking down macromolecules to create energy for our body

Wet mount

A wet mount is created by getting an empty slide, removing the film and adding a small drop of water to the slide. You then get the object you will be looking at under the microscope and place it where the water is and push down to secure it. Then you get the top slide and hold it at a 45 degree angle before placing it on top of the other slide to prevent air bubbles.

Differences between plant and animal cells

Membranes and features that plant cells have that animal cells do not:

• box shape

• cell wall

• large central vacoule rather than small vacoules

• chloroplast

Organelles work together in a cell to carry out life functions

Living systems depend on chemical reactions and energy changes that occur in cells

Microscopes

parts:

• ocular lens (eye piece)

• body tube

• arm

• objective lens

• stage

• course adjustment knob

• fine adjustment knob

• base

• light source

• diaphragm

• condenser lens

• stage clips

• revolving nose piece

Macromolecules

• carbohydrates

• lipids

• proteins

• nucleic acid (not covered in this unit)

Macromolecules are polymers- long molecules formed by linking together many smaller, similar chemical subunits, monomers

Carbohydrates

Function: provide short term or long term energy for organisms

Types

• monosaccharides, glucose

• polysaccharides, starch, cellulose, glycogen

• disaccharides, sucrose

larger polysaccharides are used mostly for energy storage (starch and glycogen)

Monomer: glucose

Lipids

function: energy storage - long term energy source for body cells, insulation and protection for cells, makes up structure of cell membranes

types

• phospholipid: composes the cell membrane of animal cells

• cholesterol: found in the cell membrane of animals, which strengthen and protect membrane

• steriods: such as testosterone or estrogen, regulates sexual function

• wax: such as cutin creates a waterproof barrier for leaves and plants

Monomer: fatty acid and glycerol

most lipids consist of 3 chains of fatty acids all connected to a glycerol molecule

the glycerol “head” is hydrophilic

the fatty acid “tails” are hydrophobic

Proteins

function: can be used as an energy source (only in emergencies), act as enzymes to facilitate chemical reactions, act as hormones- made of units called amino acids , needed for blood clotting, create hair, skin and nails, creates muscle structure, provides oxygen to blood cells

monomer: amino acid

Amino acids: to create protein you need 20 amino acids, 12 are produced from the body, 8 are needed from food

Other important compounds

• water

• glucose

• ATP

Water

function: photosynthesis, transporting molecules in animals, tugor pressure in plants (the force in the cell that pushes the plasma membrane against the cell wall) cooling effects on the body

Glucose

function: needed for aerobic respiration and photosynthesis

needed for red blood cells and the brain

ATP ( Adenosine triphosphate)

function: main energy source in animal cells, needed for aerobic respiration

currency that our cells need for energy

Aerobic respiration:

C6H12O6 + O2 = CO2+ H2O + ATP

Fluid in the human body

there are 3 main fluid compartments of your body:

• cytoplasm

• fluid between cells

• fluid in your blood