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Origin of life

Abiogenesis vs. Biogenesis

Biogenesis: Bio – life; Genesis – to form;

Biogenesis – the process that states that

living things can only be produced by

another living thing, and not by a non-living

thing.

Abiogenesis – the process that states that

living things can be produced by non-living

things.

Chemosynthetic theory- Statesthat the very

first microscopic life could have evolved as

a result of a series of chemical reactions

Amino acids ++ peptides and proteins

Hydrocarbons + sugars = fat molecules

Carbohydrates ++ starch & complex

sugars

coacervates– aggregate of molecules

Nucleic acids help in development of

coacervates

Cell

The Cell Theory -All living organisms are

composed of cells. They may be unicellular

or multicellular.

The cell is the basic unit of life.

Cells arise from pre-existing cells.

Cell structure and Function

Nucleus- Control / command center of the

cell, Stores genetic material

Cytoplasm – ‘matrix’ of the inner layer of

the cell. Cytosol – liquid portion.

Cell wall – rigid structure above cell

membrane that is thicker and more rigid

Cell membrane – semi-permeable structure

which controls the passage of materials in

and out of the cell

Golgi Apparatus – flattened sacs that store,

modify, and package products that are to be

secreted by the cells

Lysosome – bag-like cells that digest dead

organelles, organic and inorganic materials,

food, etc.

Mitochondria – powerhouse of the cell;

contains and produces ATP

Vacuoles – storage for nutrients, water, or

waste

Chloroplast – contains pigments that store

energy.

Vesicle – contains an aqueous solution using

a lipid bilayer

Ribosome –contains RNA and proteins.

Assembles protein in the cell. 2 types: Free

and bound

Cytoskeleton – provides support in the cell.

Microfilaments and Microtubules.

Centrioles – aids and functions at cell

division. Made of microtubules

Plants and Animal cells

Animal cells do not have cell walls

Animal cell round; Plant cell rectangle

Centrioles are present in all animal

cells while only a few in the plant

cells.

Animal cells do not have

chloroplasts

It is very rare for plant cells to have

cilia.

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Types of plant cells

Vascular: Xylem &Phloem

Ground:Parenchyma, Collenchyma,

Sclerenchyma

Diseases - A change in the system,

excluding an injury, that causes a disruption

on normal body functions

Pathogens/ Infectious agents

Environmental factors

Genetic

Pathogens: Bacteria, Viruses, Protists,

Large parasites, Fungi, Prions, Virion

What they do to disrupt body functions:

Rapid multiplication

Destruction of body cells and tissues

Production of poison or toxins

Koch’s postulate

Pathogen should always be found in a sick

organism

Pathogen should be isolated and grown in

pure culture

When purified pathogens are placed in new

host, the same disease should appear.

When infected pathogen is isolated, it

should be identical to the original pathogen

Germ Theory of Disease

Infectious disease is caused by germs or

pathogens

Names to remember:

IgnazSemmelweis - washing hands

Louis Pasteur - pasteurization

Joseph Lister – used sterile equipment,

antiseptics, and anesthetics in surgery

Robert Koch – worked on bacili and proved

diseases were caused by bacteria and that it

could infect any organism despite harsh

conditions

Dmitri Ivanovsky – credited as the

discoverer of viruses

Infection – modes and agents

Airborne

o droplets of pathogen

Foodborne&Waterborne

o Tape worms

o amoebiasis

Carriers or vectors

Actual contact

Defenses – vaccines, immunity, etc.

Two types of Immunity:

Innate

Acquired

Acquired (specific):

Humoral response

Cell-mediated response

Innate (Nonspecific):

External

Skin

Mucous membranes

Secretions

Internal

Phagocytic cells

Antimicrobial proteins

Natural killer cells

Inflammatory response