The Cell

Question 1

These are the building blocks of proteins.

Answer 1

Amino Acids

Question 2

What is mRNA?

Answer 2

A messenger that carries transcribed DNA to Ribosomes

Question 3

what is tRNA?

Answer 3

RNA molecules that are adapters between codons in mRNA and amino acids. They are the molecule that can make the translation between nucleotide and amino acid languages.

Question 4

What is a genetic mutation?

Answer 4

A change in DNA during replication that goes unrepaired.

Question 5

What is the most common type of mutation?

Answer 5

Point mutation

Question 6

This is an open concept cell where everything within it floats in the same area and there is no nucleus, no Organelles.

Answer 6

Prokaryotic cell

Question 7

How are RNA processed differently in Prokaryotic and Eukaryotic cells?

Answer 7

Pro - Transcription and translation occur almost simultaneously.

Euk - Transcription and translation are separated in space and time due to the nucleus which allows changes to occur to mRNA before leaving the nucleus.

Question 8

What is the plasma membrane and what does it do?

Answer 8

Crucial barrier of the cell that is flexible that regulates passage of materials in and out of cell, provides a surface for chemical reactions to occur, and helps differentiate the cell from other types.

Question 9

What is the plasma membrane made out of?

Answer 9

Phospholipids, each with a hydrophilic head, and a hydrophobic tail that form a bilayer in the cell.

Question 10

WHat is the vesicle of the cell membrane?

Answer 10

Vesicle is a cross-way for materials to transport from inside and outside the cell, but only allows certain items to enter.

Question 11

What is the function of the mitochondria?

Answer 11

“Power house” of the cell responsible for creation of ATP, has double membrane like some bacterial cells, and some contain simple circular DNA.

Question 12

What is the Lysosome of the cell?

Answer 12

“Garbage Truck” - they rid the cell of waste by breaking down molecules into their base components using strong digestive enzymes

Question 13

What is the nucleus and what does it do?

Answer 13

Largest organelle that has DNA packed into chromosomes. Surrounded by nuclear envelope, that contains large pores for RNA and macromolecules to pass through

Question 14

True or false, Prokaryotic cells involve RNA processing.

Answer 14

False.

Question 15

Differentiate between a flagellum and an Axial Filament.

Answer 15

Flagellum- Propeller to move bacteria. Long structure that extends outside the cell. Used in chemotaxis.

Axial Filaments - Runs lengthwise through the cell to propel it in a snakelike manner.

Question 16

Differentiate between Fimbriae and Pili.

Answer 16

Fimbriae - Sticky short projections used to adhere to other bacteria, substances or host. May be virulent factor

Pili - Long hollow tubules used for cell-to-cell transfer of materials

Question 17

What is the slime layer and what is it’s function?

Answer 17

Sticky substance surrounding outside of cell composed of polysaccharides, polypeptides or glycoproteins. Used to mediate adherence to other cells/surfaces, protection, prevention if dying, and reserves of carbohydrates.

Question 18

What is Biofilm? What is it’s purpose?

Answer 18

Biofilm is a collection of bacterial cells that work together as a solid mass. The purpose of a biofilm is to become more resistant than single cells to antimicrobial agents and immune responses.

Question 19

Which of the following is untrue of peptidoglycan?
A/ Single macromolecule
B/ Provides rigidity to cell
C/ Conforms to bacterial shape
D/ Is the target of antimicrobial agents

Answer 19

C/ Conforms to shape.

It actually determines the shape of the cell

Question 20

Chains of ___ & ___ attach to create cross bridges of peptidoglycan.

Answer 20

NAM & NAG

Question 21

Gram negative cells stain due to their thicker cellular membrane made of multiple peptidoglycan layers that are condensed in the staining process. True or false.

Answer 21

False. Gram negatives have a thin membrane that doesn’t retain the stain.

Question 22

What are the three bacterial shapes? Define each shape.

Answer 22

Bacillus - Rodlike
Spirillum - spiral
Coccus - Spherical

Question 23

What is the distinctive feature of prokaryotic cells?

Answer 23

They have the ability to make proteins simultaneously to reading their genetic code because there is no membrane surrounding their genetic material (Nuclear membrane).

Question 24

Gram + cells have relatively thick layer of Peptidoglycan that is adhered to the cell membrane by:
A/ Teichoic Acid
B/ Lipoteichoic Acid
C/ Periplasmic Space
D/ LPS layer

Answer 24

B/ Lipoteichoic layer (Made from Teichoic acid)

Question 25

Explain the peptidoglycan layer, along with the other two layers of Gram - bacteria.

Answer 25

The peptidoglycan layer in Gram - cells are relatively thin and surrounded by Periplasmic space, which is a gel that suspends the peptidoglycan. The outer layer of the Gram - cell is aptly named the "outer membrane" and contains LPS

Question 26

What are Lipopolysaccharides (LPS) and what do they do??

Answer 26

Made of Lipids and Sugars that extend from the outer membrane of Gram - cells. When the cell lyses, LPS release Endotoxins which can affect the host.

Question 27

Why would you not want to Kill large amounts of Gram - bacterium with antimicrobials?

Answer 27

Gram negative cells release endotoxins from their LPS upon death, making the bacterium more toxic in death than it was in life.

Question 28

What possible reactions are endotoxins responsible for in the human body?

Answer 28

Fever Vasodilation -> Shock Inflammation Blood clotting

Question 29

What are the two ribosomal subunits in prokaryotic ribosomes? How many rRNA molecules do they each possess?

Answer 29

30S and 50S 30S has 1 rRNA molecule 50S has 2 rRNA molecules

Question 30

Explain the transformation, Transduction and Conjugation processes for Gene transfer among prokaryotic cells.

Answer 30

Transformation: When recipient cell retrieves Genetic material from environment (Dead cell etc.). Transduction: Transfer of DNA from one host to another via a bacteriophage. Conjugation: Physical contact between two bacteria who exchange DNA via the Pilus system.

Question 31

Explain in detail the use of a bacteriophage in the transduction of DNA between bacterium.

Answer 31

A bacteriophage attaches to bacterial recipient and injects its DNA into the recipient cell. Bacteriophage enzymes then break down the bacteria's DNA and instructs the cell to replicate copies of the Bacteriophage (Daughter phages). The new bacteriophages will consist of the original bacteriophage DNA; however, some phages will consist of the original bacterial DNA. These are known as Transducing phages. Eventually the cell lyses and the transducing phages find other bacteria and inject the first recipient bacterial DNA into a new bacterial recipient. Thus, Transferring the DNA from one cell to another.

Question 32

Explain the process of bacterial conjugation.

Answer 32

Two bacterial cells meet and dock to one another by a pili, which is a long hollow tubule. The donor cell has what is called the F plasmid and is F+, whereas the recipient cell lacks the F plasmid and is F-. Once attached, the F plasmid in the donor cell unzips and splits into two, one of which goes to the recipient and one stays in the donor cell. Once each cell has the F plasmid strand, each cell synthesizes a complementary strand to become an F+ cell.