Cell Types/Structure

Question 1

What are/is the organelle in prokaryotic cell?

Answer 1

The only organelle is ribosomes, the type is called 70s ribosomes.

Question 2

Define organelles

Answer 2

Organelles are discrete structures in cells that are adapted to perform a specific function

Question 3

What do not meet the requirements of being classified as an organelle?

Answer 3

Cell wall - It is located outside of the membrane, it is extracellular. It is not in the cell so not an organelle

Cytoplasm - It is composed of about 80 percent water and many dissolved solutes. It is not specialized to perform a specific function

Cytoskeleton - It is composed of many different types of filaments and tubules. Not a discrete (individual, distinct) structure, so not an organelle.

Question 4

Define Nucleus

Answer 4

• Contains DNA, which stores information for making proteins
• Contains nucleolus, which is where ribosome subunits are made.
• Has a double membrane with pores, allows eukaryotic cells to separate the activities of gene transcription and translation.

Question 5

Advantages of the seperation of the nucleus and cytoplasm?

Answer 5

• The seperation protects DNA
• Allows for modification of the DNA message before leaving the nucleus.

Question 6

Define transcription

Answer 6

This is the process in the nucleus that copies DNA’s code into molecules of a type in RNA.

Question 7

Define translation

Answer 7

The process of assembling protein at ribosomes (in the cytoplasm) using the transferred code. DNA itself never leaves the nucleus.

Question 8

Benefits of the double membrane of the nucleus?

Answer 8

• Proteins are made in the cytoplasm at ribosomes
• Many substances like mRNA and ribosomes need to leave the nucleus
• Many of the above are large and therefore the nucleus needs fairly large holes or pores. Double membrane of the nucleus is used to make these pores.
• Reassembly of the membrane is easier if it is a double layer, after cell division.

Question 9

Define ribosomes

Answer 9

They catalyze/produce proteins.

They are composed of two subunits that come together to for a functioning structure.

Question 10

Define rER

Answer 10

80s ribosomes are attached to the outside.
The bound ribosomes make proteins and release them to the inside of the cisternae.
Proteins are carried through cisternae and then into vesicles which move on to the golgi apparatus.

Question 11

Define vesicles

Answer 11

Tiny sacs (single membrane layer) used to transport material/liquids

Question 12

What does rER look like?

Answer 12

Consists of flattened membrane saves (cisternae) continuous with the nuclear membrane.

Question 13

Define sER

Answer 13

They have no ribosomes
Produces lipids
Extends throughout the cell

Question 14

What does sER look like?

Answer 14

Series of connected flattened membrane sacs

Question 15

What does Golgi apparatus look like?

Answer 15

Like rER it contains flattened membrane sacs called cisternae.
They are shorter and curved with no ribosomes and many vesicles nearby

Question 16

Define Golgi apparatus

Answer 16

Stores, processes and modified the proteins. Proteins are made by vesicles from the rER.
After modification, the proteins are passed through vesicle then to the plasma membrane for secretion or repair of the cell membrane or to lysosomes.

Question 17

Define transport vesicle

Answer 17

Move substances within the cell, bud off one spot, fuse with another

Question 18

Define secretory vesicles

Answer 18

secrete substances out of the cell and create new cell membrane.

Question 19

What does lysosomes look like?

Answer 19

Small, spherical, single membranes.

Question 20

Define lysosomes

Answer 20

Formed from golgi vesicles

Obtains digestive enzymes to break down worn out organelles, or even whole cells

Question 21

What does mitochondria look like?

Answer 21

They are double membranes, smooth outer membrane with inner membrane folding inwards.
Usually oval, spherical but can vary.

Question 22

Define mitochondria

Answer 22

They produce ATP (energy molecule) by aero is cell respiration, “power house of the cell” large surface for cellular metabolism.

They contain their own DNA, can reproduce independently, produces and contains its own 70s type rivosimes

Question 23

What does chloroplasts look like?

Answer 23

Double membranes, flattened sacs called thylakoids appear in stacks.
Usually spherical/oval but can vary

Question 24

Define chloroplasts

Answer 24

They produce glucose/organic compounds by capturing light energy. Insides contain chlorophyll

Only in plant cells

Question 25

What does vacuoles look like?

Answer 25

Single membrane with fluids inside

Question 26

Define vacuoles

Answer 26

Many plants cells have large vacuoles, storage for sugars, minerals, proteins and water, gives physical support and adds structure to the cell.
Some animal cell vacuoles are used to digest food particles.
Vesicles are very small vacuoles

Question 27

Define cytoskeleton

Answer 27

Both prok/euk cells have it, not an organelle.
Helps cells maintain shape and organizes cell parts so they can move and divide.
Made of dynamic structures that can easily be constructed/deconstructed.

Question 28

Define components of cytoskeleton

Answer 28

Microtubules - Fivers made of a protein called tu in found in cytoplasm. Function in intercellular transport, cell structure, aid in cell division.

Microfilaments - smaller/thinker made of protein actin provide cell structure and cell movement.

Question 29

Define and describe how Cilia and Flagella looks like

Answer 29

They are whiplike structures projecting from cell surface.
Flagella’s are larger and usually is one (sperm) only a few
Cilia smaller and many are present
Both are used for movement

Question 30

Advantages of compartmentalizations in the cytoplasm of cells?

Answer 30

• Substances like enzyme that are needed for a particular process can be much more concentrated
• harmful substances can be kept away from other cell parts
• pH can be kept at a different level than other cell parts.
• Organelles can move around the cell
• more membrane means more surface area

Question 31

Define cell wall

Answer 31

Pro ides shape and allows the cell to withstand turbot pressure without bursting

Question 32

Define cell (plasma) membrane

Answer 32

Responsible for regulating what materials move into and out of the cell.

Question 33

Define nucleotide region (prokaryotic)

Answer 33

Contains circular DNA, genetic info codes for protein, DNA is “naked” meaning it is not wrapped with protein.