Lecture 13: Introduction To Molecular And Cellular Biology

Question 1

Who discovered the cell?

Answer 1

Robert Hooke

Question 2

The first two tenets of the cell theory was created by which two scientists?

Answer 2

Matthias Jakob Schleiden and Theodor Schwann

Question 3

What are the 3 points of cell theory?

Answer 3

1. All living organisms are composed of one or more cells
2. The cell is the most basic unit of life
3. All cells arise only from pre-existing cells - Rudolph Virchow added this tenet in 1855

Question 4

When did Schleiden and Schwann develop the first two points of the cell theory?

Answer 4

1839

Question 5

What are the basic properties of cells? (9)

Answer 5

1. Complex and organized
2. Activity controlled by genetic blueprint
3. Can reproduce - make copies of themselves
4. Assimilate and utilize energy
5. Carry out many chemical reactions (enzymes)
6. Engage in mechanical activities
7. Respond to stimuli
8. Self-regulate - determine whether they need to perform a certain activity
9. Evolve

Question 6

What does it take to make a cell? (3)

Answer 6

1. Information
2. Chemistry
3. Compartments

Question 7

All cells possess…

Answer 7

DNA

Question 8

What does DNA provide for the cell

Answer 8

Information necessary to build proteins - which is the cells primary machinery

Question 9

What is DNA the hereditary material of?

Answer 9

Genes and RNA

Question 10

What is the order of the cell replication rate for higher eukaryotic cells, bacteria and fungi?

Answer 10

Bacteria < Fungi < Higher eukaryotic cells

Question 11

DNA is transcribed to _____ which is then translated to _____

Answer 11

RNA
Proteins

Question 12

During cell division, the DNA is…

Answer 12

Replicated

Question 13

Differentiation is?

Answer 13

A cell that changes into the starting cell of other types of cells, one cell that can evolve into another type of cell. The genetic information stored in the DNA of the cell determines if the cell can differentiate, and which type of cell it can differentiate into

E.g. stem cells, which can be a variety of cells such as immune cell, sex cell, muscle cell, fat cell, bone cell, blood cell, nervous cell, epithelial cell

Question 14

Which cell type lacks the cell nucleus and therefore has no DNA?

Answer 14

Red blood cells, they eject their nucleus, through nuclear ion
Mature blood cells have no organelles and cannot synthesize RNA
Cannot divide and have limited repair capabilities
This evolution has occurred to accommodate hemoglobin carrying capacity

Question 15

Example of building blocks of the cell…? (3)

Answer 15

Amino acids - make up proteins
Nuclei Acids - carry genetic information
Lipids - help us to make cellular components

Question 16

Chemical origin of life?

Answer 16

Abiogenesis

Question 17

The primordial soup hypothesis was created by which two scientists?

Answer 17

Ovarian and Haldane

Question 18

What is the primordial soup hypothesis?

Answer 18

Primitive earth has a variety of simple organic compounds that chemically reacted with energy to synthesize more complex organic compounds from simpler inorganic precursors
Molecules: Nitrogen, Ammonia, Methane, Carbon dioxide, Water, Hydrogen gas

Question 19

Miller-Urey experiment: Pre-biotic chemistry is…

Answer 19

Chemical experiment that stimulated the conditions thought to exist on the early earth and to test the chemical origin of life under those conditions

Question 20

Compartments of a cell are defined by what factor?

Answer 20

Single or double lipid layer membrane
E.g. of compartments - Mitochondria, chloroplasts, vesicles, ER, nucleus

Question 21

What are the functions of compartments?

Answer 21

They establish physical boundaries that enable cell to carry out different metabolic activities

Generate micro-environment to spatially and temporally regulate biological processes

Question 22

Two main types of cells are…?

Answer 22

Prokaryotic - Bacteria and Archaea
Eukaryotic - Protists, fungi, plants animals, eukaryotes come from archaea, not from bacteria - archaea and bacteria are unicellular

Question 23

Eukaryotic cell vs Prokaryotic cells…

Answer 23

Eukaryotic cells have a defined nucleus
Prokaryotic cells have no defined nucleus

Question 24

Prokaryotic cells are organized into two groups which are…

Answer 24

Archaea and Bacteria
Prokaryotes came before eukaryotes

Question 25

Archaea are found…

Answer 25

In extreme environments

Question 26

Bacteria are found in…

Answer 26

Ubiquitous habitats (everywhere)

Question 27

Features of archaea

Answer 27

Have a membrane lipid with branched hydrocarbons
Chromosomes are circular
Lack a nuclear envelope
Lack membrane bound organelles
Methionine is the initiator amino acid for protein synthesis
Lack peptidoglycan in the cell wall
Growth not inhibited by streptomycin and chloramphenicol
Histones are associated with DNA
Contains several types of RNA polymerase

Question 28

Features of Bacteria

Answer 28

Chromosomes are circular
Lack a nuclear envelope
Lack membrane bound organelles

Question 29

Features of Eukarya

Answer 29

Methionine is the initiator amino acid for protein synthesis
Lack peptidoglycan in the cell wall
Growth not inhibited by streptomycin and chloramphenicol
Histones are associated with DNA
Contains several types of RNA polymerase

Question 30

Typical features of a prokaryotic cell

Answer 30

• Single cell organism
• Size: 1-10 microm
• Ribosomes are present but smaller
• Reproduce sexually and asexually
• No nucleus or organelles
• Genetic material found in nucleotide (nucleus-like)
• DNA arranged in circular chromosomes and often circular plasmids (extrachromosomal DNA)

Question 31

Typical features of a Eukaryotic cell

Answer 31

• Typically multicellular organisms, but can be unicellular as well (Protozoa, yeasts)
• Size: 10-100 microm
• Nucleus contains genetic material arranged in linear chromosomes
• Membrane-bound organelles
• Ribosomes are larger

Question 32

Animal vs. Plant cells

Answer 32

Animal:
- Lysosomes - used to degrade macromolecules
- Microvilli
Plant:
- Vacuole - like lysosome but more functions - storage - structural support
- Cell wall
- Chloroplast
- Plasmodesmata