The Cell

Question 0

Tissue

Answer 0

A group of cells with similar structure and functions with the ECM

Question 1

The cell

Answer 1

Functional and structural unit of the body

Question 2

Organ

Answer 2

A group of tissues

Question 3

System

Answer 3

Group of organs collected

Question 4

Prokaryotic cells

Answer 4

Have no true nucleus

Example: bacteria

Question 5

Eukaryotic cells

Answer 5

Have true nucleus

Example: animal cells, fungi

Question 6

Cell structure

Answer 6

Plasma membrane

Protoplasm (nucleus - cytoplasm)

Question 7

Cytoplasm (definition)

Answer 7

Fluid that fills the interior of the cell

Question 8

Cytoplasm (structure)

Answer 8

Cytosol or Matrix, in which are embedded the organelles

Cytoskeleton, defining the shape and motility

Inclusions, which are deposits of lipids, carbohydrates and pigments

Question 9

Cell membrane (synonyms)

Answer 9

Plasma membrane

Plasmalemna

Question 10

Cell membrane (function)

Answer 10

Separates the cytoplasm from its extracellular environment.

Functions as a selective barrier that regulates the passage of certain materials into and out of the cell, and facilitates the transport of specific molecules.

Keeps constant the ion content of cytoplasm, which is different from the extracellular fluid.

Question 11

Cell membrane (structure)

Answer 11

Phospholipids

Proteins

Carbohydrates

Question 12

Phospholipid bilayer

Answer 12

Amphipathic phospholipid molecules consisting of:

Polar, hydrophilic phosphate group head directed outwards

Non-polar, hydrophobic fatty acid tails forced inwards

Question 13

Macromolecules found in membranes

Answer 13

Lipids (phospholipid bilayer - cholesterol)

Proteins (transport proteins - receptor proteins - recognition proteins)

Carbohydrates (oligosaccharides of glycoproteins)

Question 14

Phospholipid bilayer (function)

Answer 14

Forms boundary to isolate cell contents from environment.

Restricts passage of hydrophilic substances across the membrane.

Question 15

Cholesterol (functions)

Answer 15

Increases bilayer strength and flexibility.

Controls the fluidity of cell membrane:
At high temperature, it stabilizes the membrane and increases its melting point .
At low temperatures, it intercalates between the phospholipids and prevents them from clustering together and stiffening.

Question 16

Integral proteins (properties)

Answer 16

Penetrate lipid bilayer, usually across whole membrane and can spam it several times (multipass transmembrane proteins).

Question 17

Peripheral proteins (properties)

Answer 17

Loosely bound to the surface of the membrane and do not penetrate its hydrophobic core.

Often found in association with integral proteins.

Question 18

Transport proteins (function)

Answer 18

Regulate movement of water soluble substances through the plasma membrane.

Question 19

Transport proteins (types)

Answer 19

Channel proteins: have pores that allow the passage of ions and small water-soluble molecules.

Carrier proteins: have binding sites specific to certain proteins, moving the molecules through the membrane. They are ADP dependent.

Question 20

Receptor proteins (functions)

Answer 20

Tigger specific cellular responses when certain molecules bind to them, by signaling inside the cell.

Question 21

Recognition proteins (function)

Answer 21

Serve as ID tags and cell-surface attachment sites.

Question 22

Carbohydrates (structure)

Answer 22

May be covalently linked to lipids (glycolipids) or proteins (glycoproteins).

Question 24

Carbohydrates (function)

Answer 24

Important for cell-cell recognition, as in the ability if a cell to distinguish one type if neighboring cells from another.

This attribute is important in cell sorting and organization as tissues and organs in development.

It is also the basis for rejection of foreign cells by immune system.