Chapter 5 - Tour of The Cell

Question 1

Most living things are how many celled organisms?

Answer 1

Most living species are single celled organisms like bacteria.

Question 2

All cells have:

Answer 2

Same basic biochemistry.
Cell membrane made of lipids.
Chromosomes, made of DNA
Ribosomes, made of RNA & proteins.

Question 3

At the cellular level there are two different types of life:

Answer 3

Prokaryotes & Eukaryotes

Question 4

What are prokaryotes?

Answer 4

Very small cells.
No nucleus.
Haploid genome ( 1 copy of genome from 1 parent).
Little or no cytoskeleton.
No inner membrane system.
No membrane-bound organelles.

‘Little boxes of biochemicals’

Question 5

What are eukaryotes?

Answer 5

Large and complex cells.
Complex nucleus.
Haploid/Diploid (2 copies, 2 parents) genome.
Mitosis & meiosis.
Complex cytoskeleton.
Inner membrane system.
Membrane bound organelles.

Question 6

What are the two different types prokaryotes?

Answer 6

Archaea & Bacteria

Question 7

All life is divided into three domains:

Answer 7

Archaea, bacteria, and eukaryotes.

Question 8

What is the endomembrane system?

Answer 8

Lipid bilayer membranes that are on the outside and inside of a eukaryote cell.

Major components include:
Rough ER
Smooth ER
Golgi Aparatus
Vacuoles & Vesicles
Nuclear Envelop (double membrane)

Question 9

Nucleus

Answer 9

Double Membrane
Has nuclear pores that go through both membranes. Pores allows molecules to go back and forth between the nucleus and the cytoplasm.
Most DNA stored here (chromosomes). 
Makes RNA copies from DNA.
Contains chromatin.

Question 10

What is the biggest protein?

Answer 10

Nuclear pore complex.

Question 11

Cytoplasm

Answer 11

Aka. Cytosol.

Semifluid, jelly-like substance.

Question 12

Plasma Membrane

Answer 12

Membrane around a cell.

Question 13

Ribosomes

Answer 13

Make proteins.
Attach to Rough ER. Free float around cytosol.
Translate RNA and use instructions to make proteins.
Contains two subunits.

Question 14

Rough ER

Answer 14

Makes glycoproteins. Makes transport vesicles. Makes cell membranes.

Question 15

Smooth ER

Answer 15

Makes lipids.
Breaks down some carbs. 
Detoxifies chemicals.
Stores calcium.
Doesn't contain ribosomes.

Question 16

Nucleolus

Answer 16

Makes ribosomes. No membrane

Question 17

Golgi Apparatus

Answer 17

Receives products from the ER and modifies them and sends them out in vesicles. Vesicles enter from cis side and leave trans side.

Question 18

Vacuoles & Vesicles

Answer 18

Membrane bags.
Big bags - Vacuoles.
Small bags - Vesicles.
Used to transport things around the cell.

Question 19

Vesicle Functions

Answer 19

Transport, Secretion, Membrane Growth, Phagocytosis, Autophagy.

Fuse with membranes and empty/receive contents.

They expand the membrane by fusing to it.

The cell can digest the contents of a vacuole by fusing it with a vesicle containing digestive enzymes.

They can use that method by digesting materials from outside (phagocytosis) or inside (autophagy).

Question 20

Peroxisomes

Answer 20

Vesicles containing enzymes. Mitochondria break down fatty acids that are shorter than 20 carbons - peroxisomes break them down to that length first if they are longer.

Question 21

Lysosomes

Answer 21

Vesicles containing enzymes for digestion at low pH.

Fuse with autophagosomes, inside the cell forming a larger vesicle where materials are digested.

Question 22

Autophagosomes

Answer 22

Double membrane vesicles that enclose cellular material for breakdown and recycling.

Question 23

Why is it important for a cell to be small?

Answer 23

Ratio of surface area to volume is critical. As a cell gets larger its surface area grows proportionally less than its volume.

Question 24

Nuclear Lamina

Answer 24

Netlike array of protein filaments that maintains the shape of the nucleus.