Intro to study of cell and microbiology

Question 1

What is the cell theory?

Answer 1

1. All organisms are composed of one or more cells.
2. The cell is the structural unit of life.
3. Cells can arise only by division from a preexisting cell.

Question 2

Cells are complex meaning…

Answer 2

Greater number of parts must be in proper place
Less tolerance for errors
More regulation
(eg. DNA replication very precise, error rate= 1/10,000,000, also most errors repaired)

Question 3

What are enzymes?

Answer 3

Molecules that greatly increase rate at which chemical rxn occurs

Question 4

How do cells acquire and utilize energy?

Answer 4

Photosynthesis=fuel for all living things

Animal cells get energy from products of photosynthesis (glucose), cells convert glucose to ATP and store it

Question 5

What is metabolism?

Answer 5

Sum of all chemical rxns in a cell

Question 6

How do cells engage in mechanical activities?

Answer 6

Dynamic activities initiated by changes in shape of motor proteins
Cells can assemble and disassemble structures, transport materials, move from one site to another

Question 7

How do cells respond to stimuli?

Answer 7

Cells are covered by receptors that interact with substances in the environment in highly specific way
Hormones, growth factors, … interact with receptors
Cell may respond by altering its metabolism, moving, or committing suicide

Question 8

How are cells capable of self regulation?

Answer 8

Cells are robust (durable) b/c they’re protected from dangerous fluctuations in composition and behaviour
If there’s fluctuations, feedback circuits return cell to appropriate state.
Maintaining a complex requires energy and regulation

Question 9

Eukaryotes vs Prokaryotes

Answer 9

Distinguished by their size and organelles they contain
Prokaryote= simple cells (bacteria)
Eukaryotes= more complex, contain membrane-enclosed organelles (animal, plant cells)
Both share same genetic language, metabolic pathways, structure features (ie. bound by plasma membrane)

Question 10

When does cell differentiation occur?

Answer 10

During embryonic development in multicellular organisms

No. and arrangement of cells relate to function and activity

Question 11

How are all differentiated cells similar?

Answer 11

Composed of same organelles

Question 12

What is cell size limited by?

Answer 12

1. Volume of cytoplasm supported by genes in nucleus
2. Volume of cytoplasm supported by exchange of nutrients
3. Distance over which substances can efficiently travel through the cytoplasm

Question 13

What is the origin of eukaryotic cells?

Answer 13

Prokaryotic cell arose before eukaryotic and gave rise to eukaryotic cells
Evidence= Both share similar genetic language, enzymes, metabolic pathways, plasma membrane

Question 14

What is the Endosymbiont Theory?

Answer 14

Certain organelles of eukaryotic cells had evolved from smaller prokaryotic cells that had taken up residence in the cytoplasm of a larger host cell
Evidence= mitochondria has its own DNA, so it could have been a prokaryote absorbed by another cell (symbiotic relationship)

Question 15

What are model organisms?

Answer 15

Species that are widely studied, well characterized, easy to manipulate

Question 16

What advantages should model organisms have?

Answer 16

1. Simple organisms
2. Fast generation time
3. large no. of offspring
4. easy to manipulate in lab
5. inexpensive