Pt 1 - intro to Cells

Cell Theory

1. all living organisms are made of one or more cells

2. cells are the basic unit of all living organisms

3. cells arise from pre-existing cells

Miller-Urey Experiments

recreated the conditions that are believed to have existed in the primitive earth

• 7 simple molecules: H2O, N2, NH3, CO, CO2, CH4, H2

Observations: With each round of the experiment, increasingly complex organic molecules were formed

Nucleic acids are necessary for______

reproduction and evolution

Central Dogma of Genetics

flow of genetic information

The first genetic system on earth was _____ based.

RNA

Evidence for RNA world:

1. some RNA molecules have enzymatic activity. aka Ribosomes

2. RNA can catalyze the polymerization of nucleotides, using itself as the template

Why are cells so small?

smaller cells have larger surface area : volume ratio.

smaller cells can interact with their surroundings more efficiently

Prokaryotes

lack a nuclear envelope, organelles, and a cytoskeleton

bacteria & archaea

• most diverse groups of cells

Eukaryotes

have a nuclear envelope, nucleus, organelles, and a cytoskeleton

Coliform Bacterium (E. Coli)

• no nucleus

• no organelles

• single chromosome

• cell wall

• capsule

Chemosynthetic bacteria

can fix CO2 without sunlight

ex: Beggiatoa

What is the defining feature of eukaryotic cells?

Nucleus

Operational Genes

meant for metabolism and other cell functions

informational genes

meant for cell division an gene expression

independent, free living cell

Single cell living

aggregation of cells of the same species but no division of functions

Colonial Living

Aggregation of cells of the same species with different somatic and reproductive functions, but not recognized true multicellularity b/c cell functions can be reversed

Colonial Living with Division of Functions

Division of functions (somatic & reproductive), terminal cell identities, and multicellularity

True Multicellularity

cells that are tightly bound by junctions and form sheets that cover the body surfaces and form the lining of the internal organs

Epithelial cells

Types of Connective Tissues

• fibroblasts

• bone

• cartilage

• adipose tissue

• areolar tissue

Blood Cell types

• red - transport O2

• white - immune responses

Mouth Epithelial Cells

Bile Duct Epithelial Cells

Intestine Epithelial Cells

cells that receive and transmit electrical and chemical signals throughout the body & are capable of generating electrical activity

Neurons

long, multinucleated cells that generate force & movement

Muscle Cells

Giardia

example of a eukaryotic cell that is anaerobic

• no mitochondria no chloroplasts

• exists before endosymbiosis

Syncytium

a multinucleated cell that is the product of the fusion of mononucleated myoblasts

Basic Properties of Cells:

• What distinguishes living cells from other non-living entities?

1. Complexity

2. genetics

3. replication

4. metabolism

5. Biochemistry

6. Function

7. response

8. Self-regulation

Which experiment demonstrates the origin of biologically important molecules?

Miller -Urey

→ suggested that organic molecules could form under the conditions that existed in the primitive earth