Lecture 7

Question 1

Internal organization of the cell: Prokaryotic

Answer 1

Absence of a nucleus, absence of discrete organelles and they’re bacteria and archaea.

Question 2

Internal organization of the cell: Eukaryotic

Answer 2

Presence of a nucleus, presence of discrete organelles and they’re animals and protists.

Question 3

Prokaryotic cells: Nucleoid

Answer 3

Within the cell’s interior. It’s a discrete concentration of DNA.

Question 4

Prokaryotic cells: Plasmids

Answer 4

Small circular molecules of DNA. These molecules carry a smaller amount of genes.

Question 5

Prokaryotic cells: Pili

Answer 5

Singular pilus. Plural pili. It’s threadlike and hollow. They’re structures that extend from one bacterial cell to another, which allow the transfer of plasmids.

Question 6

Expand on eukaryotic cells.

Answer 6

Animal cells & plants differ in different ways. However, they do share certain similarities. They both have a nucleus, organelles and the same size. They are highly structured and are divided into multiple internal compartments.

Question 7

Eukaryotic cells: Cytosol

Answer 7

Aka cytoplasmic matrix. It is the liquid found inside cells

Question 8

Eukaryotic cells: Cytoplasm

Answer 8

It’s the area within the plasma membrane. It comprises cytosol, mitochondria, plastids and other organelles (but not their internal fluids & structures). It does NOT comprise the nucleus.

Question 9

Eukaryotic cells: Endomembrane system

Answer 9

These are the organelles inside the cell that are not distinct. They communicate with each other by membrane “bridges” or by the budding of vesicles.

Question 10

Eukaryotic cells: What are vesicles?

Answer 10

Small membrane enclosed sacs.

Question 11

Eukaryotic cells: Endomembrane system, what does it include?

Answer 11

Nuclear envelope, ER, golgi apparatus, plasma membrane and vesicles.

Question 12

Eukaryotic cells: Endomembrane system: Nucleus

Answer 12

Stores DNA

Question 13

Eukaryotic cells: Endomembrane system: Nuclear envelope

Answer 13

It defines the boundary of the nucleus. It consists of two membranes (inner & outer). Each membrane is a lipid bilayer with associated proteins.

Question 14

Eukaryotic cells: Endomembrane system: Nuclear pores

Answer 14

It acts as gateways that allows molecules to enter and leave the nucleus.

Question 15

Eukaryotic cells: Endomembrane system: Nucleolus

Answer 15

It appears as a mass of densely stained granules and fibres. It is where rRNA is synthesized. It is also where large and small ribosomal subunits are assembled.

Question 16

Eukaryotic cells: Endomembrane system: Ribosomes

Answer 16

They’re made of rRNA and proteins which form large and small subunits. It is where protein synthesis happens (which is when amino acids are assembled into polypeptides).

Question 17

Eukaryotic cells: Endomembrane system: ribosomes: free ribosomes

Answer 17

They’re found floating in the cytosol, synthesized proteins that do not leave the inside of the cell.

Question 18

Eukaryotic cells: Endomembrane system: ribosomes: bound ribosomes

Answer 18

They’re attached to the ER membrane, they’re synthesized proteins that are secreted or they’re components of the plasma membrane.

Question 19

Eukaryotic cells: Endomembrane system: ER

Answer 19

It’s continuous with the nuclear envelope. It makes up >50% of total membrane in many eukaryotic cells. There are two regions: smooth or rough ER.

Question 20

Eukaryotic cells: Endomembrane system: ER: rough ER

Answer 20

It’s studded with ribosomes on the surface of the membrane. It’s where proteins are synthesized that are going to be secreted. It’s also where membranes are synthesized.

Question 21

Eukaryotic cells: Endomembrane system: ER: smooth ER

Answer 21

It’s outer surface lacks ribosomes. It functions in diverse metabolic processes, which change from cell type to cell type. It’s synthesis of lipids, metabolism of carbohydrates, detoxification of drugs and poisons, and storage of calcium ions.

Question 22

Eukaryotic cells: Endomembrane system: golgi apparatus

Answer 22

It looks like a series of flattened-membrane sacs. This is called cisternae. Stacked cisternae are surrounded by many small vesicles. It is not continuous with the ER, its is own thing. It’s the next place that most vesicles go that bud from the ER.

Question 23

Eukaryotic cells: Endomembrane system: What are the 3 main functions of golgi apparatus?

Answer 23

1. It further modifies the lipids and proteins that are made by the ER
2. It acts as a sorting station
3. It’s where carbohydrates synthesize

Question 24

Eukaryotic cells: Endomembrane system: lysosomes

Answer 24

It is specialized vesicles that come from the golgi. It’s purpose is for intracellular digestion: degraded, damaged or unneeded macromolecules, bacteria or other smaller organisms that have been engulfed. Macromolecules consists of proteins, nucleic acids, lipids and complex carbs. The membrane-bounds-proton-pumps keep the internal environment at an acidic pH of around 5 (optimal pH for degrading enzymes).

Question 25

Eukaryotic cells: Endomembrane system: Phagocytosis

Answer 25

Lysosomes carry out intracellular digestion in a variety of ways. Amoebas + other protists and certain white blood cells, are able to extend their plasma membranes and engulf smaller organisms through phagocytosis. Some of these organisms can be bacteria or damaged cells.

Question 26

Eukaryotic cells: Endomembrane system: Autophagy

Answer 26

Lysosomes also use their hydrolytic enzymes to recycle the cell’s own organic material. (This is called autophagy)

Question 27

Eukaryotic cells: Endomembrane system: Vacuoles

Answer 27

They’re large vesicles that come from the ER and golgi. It has different functions, such as; food vacuole, contractile vacuole and central vacuole.

Question 28

What are Mitochondria?

Answer 28

It’s not part of the endomembrane system. It’s where cellular respiration occurs. Cellular FINISH