organelles of neurons

Question 1

examples of organelles without membranes

Answer 1

ribosomes, cell wall, cytoskeleton

Question 2

examples of single membrane bound organelles

Answer 2

vacuole, lysosome, golgi apparatus, endoplasmic recticulum

Question 3

examples of double membrane bound organelles

Answer 3

nucleus & mitochondria

Question 4

features of the plasma membrane

Answer 4

• semi-permeable phospholipid bilayer
• small hydrophobic/non polar molecules can pass via diffusion - O2, CO2
• small polar molecules -> water -> slowly
• restrict movement of highly charged molecules e.g. ions + large polar molecules
• selective transport

Question 5

what creates a cell membrane to be fluid

Answer 5

• temperature (lower temp phospholipids move closer together & vice versa)
• proportion of saturated & unsaturated fatty acids (more unsaturated (double bond kinks) fatty acids -> fluidity of membrane increase)
• cholesterol (holds phospholipids together, restricting movement)

Question 6

name all the parts that make up the nucleus

Answer 6

ribosomes, chromatin, nucleoplasm, nuclear envelope, nuclear pores, nucleolus

Question 7

what is the endomembrane system and what does it include?

Answer 7

• organelles work together to modify, package & transport lipids & proteins
• nuclear envelope, endoplasmic recticulum, golgi apparatus & lysosomes

Question 8

what happens in the smooth ER

Answer 8

• synthesis of carbohydrates, lipids & steroid hormones
• detoxification of medications & poisons
• storage of calcium ions

Question 9

what are the four stages of mitochondria cellular respiration

Answer 9

glycolysis, pyruvate oxidation, krebs cycle, oxidative phosphorylation

Question 9

what happens to proteins in the golgi apparatus

Answer 9

enters cis face and undergo modification, short chain of sugar molecules might be added/ removed or phosphate groyps attached as tags. then they are sorted & packaged as vesicles and leave trans face

Question 10

definition of diffusion

Answer 10

diffusion through a permeable membrane moves a substance from an area of high conc down conc gradient

Question 11

how does a hypertonic, isotonic and hypotonic solution environment affect a cell

Answer 11

hypertonic -> water leave cell and shrinks
isotonic -> no net movement or change
hypotonic -> water enter cell and swells

Question 12

what two types of protein assist with facilitated transport

Answer 12

• channel protein
• carrier protein (may change shape of the molecule as they move through membrane)

Question 13

what is a uniporter, symporter and antiporter

Answer 13

uniporter -> carry one molecule
symporter -> carries two different molecules/ions both in same direction
antiporter -> carries two different molecules/ions in different directions

Question 14

how can active transport create an electrochemical gradient

Answer 14

active transports of ions such as sodium and potassium

Question 15

what is secondary active transport

Answer 15

electrochemical gradient created by primary active transport, can move other substances against conc. gradients (aka co transport)

Question 16

what is the phagocytosis process

Answer 16

• particle ingested by phagocyte after antigens are recognised -> forms phagosome
• lysosome + phagosome -> phagolysosome
• particles broken down and resulting waste is discharged through exocytosis

Question 17

what is pinocytosis

Answer 17

uptake of extracellular fluids and small molecules by a cell

Question 18

function of peroxisomes

Answer 18

• main function is the lipid metabolism and the processing of reactive oxygen species
• they take part in various oxidative processes
• take part in lipid metabolism and catabolism of D-amino acids, polyamines and bile acids.