cells & molecules lvl 1

Question 1

describe the structure present in all cell types

Answer 1

cells can be eukaryotic or prokaryotic
e.g of eukaryotic is plants fungi and algae and prokaryotic is archea
eukaryotic - nuclear membrane and membrane bound organelles
prokaryotic - lack nuclear membrane and no membrane bound organelles
cell membrane- forms selective barrier, has phospholipid bilayer, embedded in the membrane are proteins which act as receptors and detect chemical messengers & signalling molecules in the extracellular fluid

Question 2

what is the other name for cell membrane

Answer 2

plasma membrane or plasmalemma

Question 3

describe the role of cytoskeleton

Answer 3

supports and maintains cell shape
movement and positioning

Question 4

give 2 examples of surface projections on eukaryotic and prokaryotic

Answer 4

cilia : short, moves in stiff strokes and present in many

flagella : long threadlike structures, one or two present (e.g sperm)

Question 5

describe the nucleus

Answer 5

contains DNA
enclosed in nuclear membrane
associated with the RER

Question 6

roles of the RER

Answer 6

Modifies proteins AFTER they have been synthesised

Question 7

roles of golgi apparatus

Answer 7

packages up proteins in preparation for transport out of the cell

Question 8

roles of SER

Answer 8

production of steroid hormones and lipids and metabolism of toxins

Question 9

describe the structure of the mitochondria

Answer 9

bound by phospholipid bilayer
the outer membrane has pores
the inner membrane has cristae (folds)
it is the primary site of cellular respiration

Question 10

where is the matrix located and describe its role

Answer 10

in the mitochondria
contains most of the enzymes required for metabolizing food molecules

Question 11

what are stem cells and gives example of their usage

Answer 11

cells which can differentiate
can be used for treatment of cancer

Question 12

what does the term multipotent mean

Answer 12

differentiate into many

Question 13

what does the term pluripotent mean

Answer 13

differentiate into any

Question 14

undifferentiated cells result in what? describe if these are genetically different or not

Answer 14

formation of daughter cells which are genetically identical.
different gene expression and internal environment causes the daughter cells to develop into different cell types

Question 15

what is the difference between apoptosis and necrosis

Answer 15

apoptosis is programmed cell death & is controlled (normal process)

necrosis is the untimely death of cells in response to injury or infection(not a normal process)

Question 16

how many functional groups can biomolecules obtain?

Answer 16

more than one

Question 17

describe the importance of configuration and conformation in biomolecules

Answer 17

biomolecules contain a C=C bond which means they cannot rotate.
they have two configurations, cis & trans
(in cis the group are same side of double bond but trans the groups are in opposite directions)

configuration is important biologically due to Rhodopsin. Once exposed to light alters the configuration of the retinal (from cis to trans) which sends signals to allow us to see

Question 18

symmetrical carbon molecules and asymmetrical ones are called what?

Answer 18

symmetrical - achiral
asymmetrical - chiral

Question 19

what form (D form or L form) do monosaccharides occur in?

Answer 19

D- form

Question 20

what form (D form or L form are amino acid residue ?

Answer 20

L- form

Question 21

list the 5 chemical reactions of life

Answer 21

• redox reactions
• making and breaking C-C bonds
• Internal rearrangements
• group transfer
• condensation and hydrolysis reactions

Question 22

state 3 types of carbohydrates and their examples

Answer 22

polysaccharides e.g glycogen
monosaccharide e.g glucose
disaccharide e.g sucrose

Question 23

describe the structure of nucleic acids

Answer 23

forms the core structure of DNA & RNA

-they’re polymers of nucleotide monomers linked by 3’ 5’ phosphodiester bonds

Question 24

list the two purines and the two pyrimidines in RNA

Answer 24

purines = adenine & guanine

pyrimidines= uracil and cytosine

Question 25

what are lipids

Answer 25

repeating units of fatty acids

Question 26

give examples of the type of bonds lipid molecules can be

Answer 26

saturated : single bonds
mono saturated: one double bond
poly saturated: more than one double bond

Question 27

the more double bonds in a chain does what to the flexibilty of the molecule ?

Answer 27

makes it more bendy

Question 28

write what a phospholipid is made up of

Answer 28

glycerol + 2 fatty acid chains(2ACEYTL) + phosphate group

Question 29

describe sterol lipids
and give example
and how many fused rings do they have

Answer 29

theyre structrual lipids
has a nucleus which is 4 fused rings
cholesterol is an example the most important in humans