The Eukaryotic Cell

Question 1

What is the plasma membrane in the eukaryotic cell made of?

Answer 1

Lipids, proteins and carbohydrates.

Question 2

What is the role of lipids in the plasma membrane?

Answer 2

The phospholipids form a double layer called lipid bilayer. Cholesterol molecules are intercalated between it.

Question 3

What is the role of proteins in the plasma membrane?

Answer 3

The integral/transmembrane proteins pass through the membrane from side to side, while the peripheral proteins stick to the side.

Question 4

What is the function of carbohydrates in the plasma membrane?

Answer 4

They form part of the outer side of the membrane, forming the glucocalix.

Question 5

What two elements are in the cytoplasm?

Answer 5

The organelles and the cytoskeleton.

Question 6

What is the nucleolus?

Answer 6

A dense mass formed of RNA and proteins.

Question 7

What is the chromatin?

Answer 7

DNA fibers that bind to histones. When it condenses it forms chromosomes.

Question 8

What is the nucleoplasm?

Answer 8

The liquid medium inside the cell. This is where the chromatin floats.

Question 9

What is the nuclear envelope?

Answer 9

The double membrane surrounding the nucleus.

Question 10

What are the nuclear pores?

Answer 10

Small holes interrupting the envelope that allow the entrance and exit of substances.

Question 11

What is the endoplasmic reticulum?

Answer 11

A set of membranous sacs that surround the nucleus.

Question 12

What is the difference between the rough and the smooth E.R.?

Answer 12

The rough E.R. has ribosomes attatches to it and participates in manufacturing proteins. The smooth E.R. does not have ribosomes and its function is to synthesise lipids.

Question 13

What is the golgi apparatus?

Answer 13

A set of membranous sacs that are interconnected. It modifies substances from the E.R. and it secretes small vesicles.

Question 14

What is the mitochondria?

Answer 14

A membranous organelle that carry out cellular respiration.
Equation: glucose + O2 = CO2 + H2O + Energy.

Question 15

What is the centrosome?

Answer 15

It is composed of two cylinders perpendicular to each other. They are called centrioles. The centrosome participates in cell division.

Question 16

What is the cytoskeleton?

Answer 16

Protein fibers that support the cell and allow the movement of the organelles inside it.

Question 17

What are the vesicles?

Answer 17

Small membranous sacs that store and transport substances.

Question 18

What are the lysosomes?

Answer 18

A special type of vesicles that carry out intracellular digestion.

Question 19

What are the ribosomes?

Answer 19

Structures formed by RNA and proteins, their function is to synthesize proyeins. They can be loose in the cytoplasm or glued to the E.R.

Question 20

What are the cilia and the flagella?

Answer 20

Proteic extensions of the cytoskeleton that help with cell mobility.

Question 21

Apart from the previous organelles, what three special organelles do plant cells have?

Answer 21

Vacuoles, the cell wall and plasts.

Question 22

What is the vacuole?

Answer 22

A vesicle that stores mainly water but also other substances, including wastes.

Question 23

What is the cell wall?

Answer 23

It is made of cellulose and protects the cell without isolating it. It is rigid and gives the cell its well-known polygonal shape.

Question 24

What are plasts?

Answer 24

They are organelles that accumulate substances.

Question 25

What are chloroplasts?

Answer 25

They are plasts that carry out photosynthesis thanks to chlorophyll.
Equation: H2O + mineral salts + solar energy = Glucose + O2.