This discussion is closed.
samfreak
Badges: 0
Rep:
?
#2921
Report 6 years ago
#2921
how the structure of polymers are related to theie functions? any ideas what i could include? :-)

Posted from TSR Mobile
0
Anjna
Badges: 9
Rep:
?
#2922
Report 6 years ago
#2922
can someone explain Q 5bii) pleaseeee http://filestore.aqa.org.uk/subjects...5-QP-JUN12.PDF
0
samfreak
Badges: 0
Rep:
?
#2923
Report 6 years ago
#2923
structure n function of membranes in organisms?

Posted from TSR Mobile
0
MathMad
Badges: 0
Rep:
?
#2924
Report 6 years ago
#2924
(Original post by sals1234)
Hey guys! what sort of things could you write about in an essay question on the roles of membranes in living organisms?
31. The part played by the movement of substances across cell membranes in the functioning of different organs and organs systems (June 2008).
Plasma membranes and movement across Gaseous exchange system/ lungs Digestive system/small intestine Blood vascular system Transpiration/root/stem Mass flow/leaf/stem Nervous system/eye Excretory system/ kidney Muscle systems Liver, blood glucose Root mineral ions Lungs cystic fibrosis
Any other sensible example of the movement of substances across cell membranes in the functioning of different organs and organ systems should be credited. In a good essay, the emphasis should be on movement across membranes involving organ function.
0
jonnyb123
Badges: 9
Rep:
?
#2925
Report 6 years ago
#2925
(Original post by HELPIMSTUCK)
Nucleic Acids (DNA/RNA)
Proteins (polypeptides)
Carbohydrates (Polysaccharides - Cellulose, Starch, Glycogen)
Ah right thanks!

(Original post by Hippokrates)
The different ways in which organisms use ATP OR ATP and its roles in living organisms
The nature/structure of ATP and its importance as energy currency. Production and use of ATP in cytoplasm by glycolysis Production of ATP by mitochondria in Krebs cycle and ETS – aerobic respiration. Anaerobic respiration. Role of chloroplasts in ATP production via light independent reaction Uses e.g. Active transport (carrier protein shape changes), Nerve action (maintaining resting potentials via Na+/K+ pump and resynthesis of ACh), selective reabsorption by nephron, absorption by gut, Calvin cycle, muscle contraction (cross bridge formation), Biosynthesis of organic compounds, Contractile vacuoles, Translocation (loading of phloem), cell division (movement of chromosomes via spindle), CP formation in muscles, Nitrogen fixation (Blue-green algae), Kidney function, movement of sperm, secretion of digestive enzymes in saprophytic fungi, cilia and flagella action
All of those in bold aren't in are syllabus are they?! I don't know about any of them .That essay would be like 1/2 off syllabus content! (also by CP formation in muscles did you mean phosphocreatine? Wouldn't that be PC?)...
0
henryoloyede
Badges: 0
Rep:
?
#2926
Report 6 years ago
#2926
(Original post by jonnyb123)
Thanks for this, the first 2 look hard! One question: polymers? I'm thinking of chemistry here ha, what are polymers in biology?
Things like: DNA, Proteins, Cellulose, basically any long molecule made from smaller repeat units. (Repeat units would be: Nucleotides for DNA, Amino Acids for proteins, etc.)
0
Anjna
Badges: 9
Rep:
?
#2927
Report 6 years ago
#2927
can someone just go through how adrenaline increases blood glucose conc
0
sals1234
Badges: 1
Rep:
?
#2928
Report 6 years ago
#2928
(Original post by MathMad)
31. The part played by the movement of substances across cell membranes in the functioning of different organs and organs systems (June 2008).
Plasma membranes and movement across Gaseous exchange system/ lungs Digestive system/small intestine Blood vascular system Transpiration/root/stem Mass flow/leaf/stem Nervous system/eye Excretory system/ kidney Muscle systems Liver, blood glucose Root mineral ions Lungs cystic fibrosis
Any other sensible example of the movement of substances across cell membranes in the functioning of different organs and organ systems should be credited. In a good essay, the emphasis should be on movement across membranes involving organ function.
Thank you!!!
0
gingerandice
Badges: 1
Rep:
?
#2929
Report 6 years ago
#2929
(Original post by Anjna)
can someone just go through how adrenaline increases blood glucose conc
mechanism: second messenger model: during stress/ see a tiger licking its lips at you, the adrenal glands secrete adrenaline into the blood plasma, which binds to receptors on the cell surface membrane of its target cells (e.g livercells) this forms a complex with activates an enzyme that converts ATp into cylic AMP. Cylic amp acts as a second messenger , activating enzymes that convert glycogen to glucose through the process of glycogenlysis.
0
marleyxd
Badges: 0
Rep:
?
#2930
Report 6 years ago
#2930
(Original post by DavidYorkshireFTW)
If your asking for cystic fibrosis then:
A faulty gene cause the cystic fibrosis transmembrane conductance regulator (CFTR) not to work properly, meaning chloride ions are transported from the cilia into the epithelial cells i think in the trachea, meaning water (moisture) in the cilia diffuses from the cilia into the epithelial cells via osmosis, because the chloride ions make the water potential lower in the epithelial cells, meaning mucus produced by (goblet?) cells is sticky. I am not sure, but i think that's right, but i wrote that from a disease point of view, so just pick out the useful stuff
This is wrong... Cystic Fibrosis is caused by the faulty gene (CFTR) NOT producing any chloride ions. This means that water isn't transported out of the cells so the membrane is dry, producing sticky mucus.
0
jonnyb123
Badges: 9
Rep:
?
#2931
Report 6 years ago
#2931
(Original post by Anjna)
can someone just go through how adrenaline increases blood glucose conc
Adrenaline acts as a first messenger and binds to receptors on the plasma membrane, which activates an enzyme on the other side of the membrane that converts ATP to cyclic AMP. This acts as a second messenger and activates enzymes which convert glycogen into glucose (glycogenolysis.) It's actually a chain of enzyme controlled reactions I think but we don't have to know it in detail
0
gingerandice
Badges: 1
Rep:
?
#2932
Report 6 years ago
#2932
(Original post by marleyxd)
This is wrong... Cystic Fibrosis is caused by the faulty gene (CFTR) NOT producing any chloride ions. This means that water isn't transported out of the cells so the membrane is dry, producing sticky mucus.
I thought the cftr was non functional, so does not allow the transport of chloride ions across the epithelial membrane due to its shape being unresponsive ? not that it produces chloride ions?
0
Hippokrates
Badges: 14
Rep:
?
#2933
Report 6 years ago
#2933
(Original post by jonnyb123)
Ah right thanks!



All of those in bold aren't in are syllabus are they?! I don't know about any of them .That essay would be like 1/2 off syllabus content! (also by CP formation in muscles did you mean phosphocreatine? Wouldn't that be PC?)...
I didn't read it but it's a real markscheme I didn't write it. I think an essay on ATP would be mean there's not that much to write.
0
pjanoo
Badges: 2
Rep:
?
#2934
Report 6 years ago
#2934
(Original post by Anjna)
can someone just go through how adrenaline increases blood glucose conc
Adrenaline binds to adrenaline receptors on the surface membrane of target liver/muscle cells, This binding on the membrane actually activates an enzyme inside the cell.

This activated enzyme can now go on to catalyse the conversion of ATP to cAMP (all inside the cell)

cAMP is the 2nd messenger (where adrenaline was the 1st messenger) that activates enzymes for reactions: glycogenolysis (glucose from glycogen) and gluconeogenesis (glucose from amino acids and lactate).

Glucose leaves the cell through glucose-transporter proteins in the cell surface membrane and so blood glucose concentration is increased. Hope this helps!
0
DavidYorkshireFTW
Badges: 16
Rep:
?
#2935
Report 6 years ago
#2935
(Original post by Anjna)
can someone just go through how adrenaline increases blood glucose conc
I think.. Adrenaline and glucose bind to the specific receptors on the cell membrane of the liver, it then activates an enzyme called adenylate cyclase, which convert ATP into the secondry messanger- cyclic AMP (cAMP), which causes a cascade of reactions, which causes glycogenolysis- the break down of glycogen into glucose, which is then released by the cell into the blood, increasing blood glucose.
That's pretty long winded, there is probably a simplified one but yeh
Hope that helped!
0
PinkNailPolish
Badges: 0
Rep:
?
#2936
Report 6 years ago
#2936
Is a promoter the same as a primer?
0
marleyxd
Badges: 0
Rep:
?
#2937
Report 6 years ago
#2937
(Original post by gingerandice)
I thought the cftr was non functional, so does not allow the transport of chloride ions across the epithelial membrane due to its shape being unresponsive ? not that it produces chloride ions?
Yeah thats what i was saying! It doesn't produce chloride ions
0
DavidYorkshireFTW
Badges: 16
Rep:
?
#2938
Report 6 years ago
#2938
(Original post by marleyxd)
This is wrong... Cystic Fibrosis is caused by the faulty gene (CFTR) NOT producing any chloride ions. This means that water isn't transported out of the cells so the membrane is dry, producing sticky mucus.
No where did i say chloride ions were produced, water isn't transported out because of the faulty chloride ion channels don't transport the chloride ions out of the cell, producing sticky mucus as there is no water. I got it directly from an AQA Nelson Thornes Human Biology textbook ..
0
pjanoo
Badges: 2
Rep:
?
#2939
Report 6 years ago
#2939
(Original post by PinkNailPolish)
Is a promoter the same as a primer?
Not really no. A primer is something 'man-made' if you like. It's something we add to a PCR mixture to kick-start DNA polymerase, whereas a promotor is a region on your DNA to kick-start RNA polymerase/transcription of DNA to mRNA.
1
F1's Finest
Badges: 21
Rep:
?
#2940
Report 6 years ago
#2940
(Original post by gingerandice)
I thought the cftr was non functional, so does not allow the transport of chloride ions across the epithelial membrane due to its shape being unresponsive ? not that it produces chloride ions?
You're correct, the CFTR is a gene that codes for a protein that pumps Cl- out of the epithelial cells. There's no such thing as a GFTR pump that 'makes Cl ions' lmfao
0
X
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Cardiff Metropolitan University
    Undergraduate Open Day - Llandaff Campus Undergraduate
    Sat, 19 Oct '19
  • Coventry University
    Undergraduate Open Day Undergraduate
    Sat, 19 Oct '19
  • University of Birmingham
    Undergraduate Open Day Undergraduate
    Sat, 19 Oct '19

Have you made up your mind on your five uni choices?

Yes I know where I'm applying (56)
67.47%
No I haven't decided yet (18)
21.69%
Yes but I might change my mind (9)
10.84%

Watched Threads

View All