Cell

Question 1

What is a cell

Answer 1

smallest functional unit of the body capable of lone survival. Studied in cytology

Question 2

role of the plasma membrane

Answer 2

flexible outer surface that separates the internal environment of cell to its external environment
regulates transport of materials in and out of cell = keep appropriate environment
enables communication between cells and their environment

Question 4

How do cells communicate?

Answer 4

through cell signalling, cells will release chemical messengers that will attach to receptors with a complimentary shape (only present on target cells). ligand = complementary molecule of a receptor
These messages will trigger a change inside the cell

Question 5

cell types within the human body

Answer 5

Exocrine
Enteroendocrine
Muscle cells
Hepatocytes
Etc

Question 6

which organelles are membrane bound

Question 7

what organelles are apart of the Golgi complex

Question 8

what cells have microvilli

Answer 8

cells in small intestine

Question 9

what cells have flagellum

Answer 9

makes cells motile e.g. sperm cell

Question 10

cells with cilia

Answer 10

cells in respiratory tract

Stomach
Intestines

Question 11

Structure of cell/ plasma membrane

Answer 11

Membrane composed of lipid bilayer formed from phospholipid, cholesterol, glycolipids

Question 12

properties of phospholipid

Answer 12

Phosphate head = hydrophilic (can interact with water)
Fatty acid tails = hydrophobic

Question 13

Structure of cholesterol

Answer 13

Four carbon rings, hydrocarbon tail, hydroxyl group

Question 14

Property of cholesterol

Answer 14

provide stability to the cell membrane and regulates fluidity by embedding itself between the phospholipids

Question 15

What are amphipathic molecules

Answer 15

molecules with polar and non polar parts - each of the lipids in the plasma membrane are amphipathic

Question 16

why is the property of phospholipids important

Answer 16

the molecule will arrange itself with heads facing towards aqeous environment and tails facing away so a phospholipid bilayer formed

Question 17

How is cholesterol amphipathic

Answer 17

Weakly amphipathic as they have a small hydroxyl group that acts as its polar region (forming hydrogen bonds with heads of phospholipid and glycolipids)
The non polar region is the steroid rings and hydrocarbon chains

Question 18

what is glycoprotein and glycolipids

Answer 18

glycoprotein = protein attached to carbohydrate. The protein section will be embedded into the membrane.
- Can be extrinsic or intrinsic
Glycolipid = carbohydrate attached to phospholipid.
As receptors, it will be present on the side of the cell membrane facing extracellular fluid
- Extrinsic

Question 19

Peripheral vs integral proteins vs transmembrane

Answer 19

Integral proteins are embedded into the membrane
-these can be transmembrane if they are embedded across the two layers of the membrane
Peripheral proteins attached to polar heads of phospholipids or to integral proteins

Question 20

what is the glycocalyx

Answer 20

The sugary coating of the cell created by glycoproteins and glycolipids.

Question 21

Function of glycocalyx

Answer 21

The pattern of the carbohydrates differ from one cell to another thus acts to differentiate between different cells

Enable cells to attach to each other

Protects cells from being destroyed by enzymes in extracellular fluid

In some cells, it will attract liquid to the surface to prevent cells drying out

Question 22

what are channel proteins

Answer 22

water filled hydrophilic channels that allow ions to move into and out of cell

Question 23

What are carrier proteins

Answer 23

Transporters of polar substances and ions that will change shape to carry the substance across membrane

Question 24

How are carrier proteins used in active transport

Answer 24

ATP hydrolyses into ADP + Pi, Pi will attach to the carrier protein causing it to change shape.

Question 25

Enzymes in membrane

Answer 25

enzymes can be integral or peripheral depending on the side of the cell it faces - if it faces toward cytosol, it is integral

Question 26

Types of movements in and out of cell

Answer 26

Active = involves energy in form of ATP Passive = doesn't involve cellular energy in form of ATP

Question 27

Passive movement

Answer 27

Moves down concentration gradient e.g. simple diffusion and osmosis

Question 28

Active movement

Answer 28

requires energy as molecules move against the concentration gradient

Question 29

what is simple diffusion

Answer 29

lipid soluble molecule moves through cell membrane (from high to low concentration) into cell *until equally spread out e.g. diffusion of O2 and CO2 across alveolar

Question 30

How do lipid insoluble molecules enter cell by simple diffusion

Answer 30

transport via the channel proteins e.g. ions, This is facilitated diffusion

Question 31

what is osmosis

Answer 31

movement of water molecules though a semi - permeable membrane. The membrane can only allow water molecules to pass through not solute or water bound to solute From an area of high water concentration to area of low water concentration

Question 32

whis cell transport important

Answer 32

maintain homeostasis

Answer 33

Formed of Ribosomal RNA and proteins formed of the larger and smaller subunit

Question 34

function of ribosome

Answer 34

Use amino acids in the cell to translate mRNA into proteins forming a polypeptide chain. attach amino acids together

Question 35

free floating vs membrane bound ribosomes

Answer 35

Attached to ER: proteins for specific organelles, embedding in membrane and excretion out of cell Free floating: proteins are used in cytosol

Question 36

mitochondria

Answer 36

double membrane mound organelles synthesising ATP the muscle cells contains the most mitochondria - energy for contraction

Question 37

What 3 processes that create ATP

Answer 37

glycolysis = cytosol krebs cycle = mitochondria electron transport chain = mitochondria *krebs and ETC generate most ATP

Question 38

what is nucleus

Answer 38

double membrane bound surrounded by nuclear envelope Contains DNA which controls the cell e.g. codes proteins

Answer 39

DNA used to create mRNA which can leave the nucleus and attach (?) to ribosome where it can be translated into polypeptide chain

Question 40

what is specialisation of cells

Answer 40

process that allows cell to function. The genes (functional units) in DNA will be switched on or off to code for different proteins which will enable cell to carry out a specific function or structure

Question 41

organic compounds

Answer 41

those made up of BOTH carbon and hydrogen These are synthesised in the human body via covalent bonds

Question 42

inorganic compounds

Answer 42

those that do not contain both carbon and hydrogen e.g. water, salt, acid and bases

Question 43

What are linkers

Answer 43

Integral or peripheral proteins that anchor proteins in the plasma membrane of neighbouring cells or to protein filaments inside and outside of cell.

Question 44

what are buffers

Answer 44

compounds that compensate for changes in PH

Question 45

What is the optimum temperature for most enzymes in the body

Answer 45

37 degrees