Turn on thread page Beta
    • Thread Starter
    Offline

    2
    ReputationRep:
    1) Pancreas and small intestine
    a. Maltase has a specific tertiary (3D) structure and so forms a unique active site, only which a complementary substrate can enter – Maltose. Forming Enzyme-substrate complexes.

    2) RER, golgi apparatus and mitochondria.
    a. Magnification of 2000 (1/100)/5x10^-6) = 2000.

    3) Lactose (disaccharide) hydrolysed into glucose and galactose which are both reducing sugars > whilst lactose remains undigested and so tastes less sweet.
    i. Large surface area, and so increases exposure of the lactase enzyme to the lactose.
    ii. Prevents contamination of the milk, doesn't contain lactase enzymes.
    iii.

    4) [Fish question]
    a. Conclusions:
    i. People who didn’t eat fish are more likely to suffer from asthma [data]
    ii. Can’t remember x2
    b. Test for lipids: grind the fish up, add ethanol and water and mix. A cloudy white colour/emulsion if form oils are present as they’re lipids.

    5)[Whooping cough]
    i. Number of cases decreases, elaborated that point.
    ii. Religious, ethical, medical objects and so more people reject vaccinations.

    The peaks) Number of vaccinations increased + how a vaccination works, produces memory cells which produces antibodies unique to the antigens of the bacteria.

    Last part) Herd Immunity, majority of population are vaccinated in a given time period and so the number of cases is minimal this reduces the transmission of Whooping cough as no-one virtually is infected by it.

    6)[Honey thing] Water potential decreases and so water moves in by osmosis from an area of higher WP to an an area of lower WP, down the concentration gradient. I went onto speaking about osmositc lysis which is apparently incorrect.

    7)Heartbeat question - the range was like 71 - 53, can't entirely remember for 100%.i. The percentage decrease for women = 13.6%.ii. Stroke volume increases due to deeper contractions of the Heart Muscle, greater surge of blood per contraction.

    8) Antigens/bacteria which antibodies are required for.
    a. Facilitated diffusion, molecules bind onto the carrier proteins which causes them to change in shape and release to the opposite side – down the concentration gradient [high concentration to a lower concentration] from the blood – liver cells I think.

    Reducing risk of CHD) less deposits of fatty substances such as LDL cholesterol and so likelihood of atheroma's developing is minimal and so reduces the risk of aneurysms and thrombosis.

    9) Cell fractionation separates organelles in order of mass.
    a. Animals cells placed in cold, isotonic and buffered solution – reduce enzyme activity, prevent osmotic movement (cells bursting or shrinking) and maintain contain pH, respectively.
    b. Cells broken down in a Homogeniser which releases the organelles.
    c. Resultant fluid, homogenate, filtered to remove whole cells and debris.
    d. Homogenate spun in tubes in a Centrifuge. Nuclei sets at the bottom (heaviest organelle) as sediment. The reminisce known as supernatant which is removed and spun once more at a faster speed – Mitochondria sets at the bottom – sediment.

    10) TEM has the highest resolving power and magnification, as it uses a beam of electrons which has a short wavelength and so diffraction is considerably lower.
    a. TEM works by penetrating electrons through the specimen, some regions absorb the electrons appearing darker whilst other regions allow electrons to directly penetrate through, appearing brighter – onscreen image produced.
    b. Limitations: black and white, 2D imagine [EXPLAIN]
    c. Complex staining process – artefacts + specimen needs to be thin [EXPLAIN]


    Misc questions:
    -Asthma = muscles surrounding the bronchioles contract.
    -Control group = treat exactly the same, but replace drug with a placebo.
    -Pathogen = damage host tissues/cells and produce toxins.
    -Using % = used for a comparison as the starting values are different, and so it's easier.
    Offline

    12
    ReputationRep:
    (Original post by S.Ahmad)
    1) Pancreas and small intestine
    a. Maltase has a specific tertiary (3D) structure and so forms a unique active site, only which a complementary substrate can enter – Maltose. Forming Enzyme-substrate complexes.
    2) Ribosomes, golgi apparatus and mitochondria.
    a. Magnification of 2000 (1/100)/5x10^-6) = 2000.
    3) Lactose (disaccharide) hydrolysed into glucose and galactose which are both reducing sugars > whilst lactose remains undigested and so tastes less sweet.
    4) [Fish question]
    a. Conclusions:
    i. People who didn’t eat fish are more likely to suffer from asthma [data]
    ii. Can’t remember x2
    b. Test for lipids: grind the fish up, add ethanol and water and mix. A cloudy white colour/emulsion if form oils are present as they’re lipids.
    5)
    6)
    7)
    8)
    9) Antigens/bacteria which antibodies are required for.
    a. Facilitated diffusion, molecules bind onto the carrier proteins which causes them to change in shape and release to the opposite side – down the concentration gradient [high concentration to a lower concentration] from the blood – liver cells I think.
    10) Cell fractionation separates organelles in order of mass.
    a. Animals cells placed in cold, isotonic and buffered solution – reduce enzyme activity, prevent osmotic movement (cells bursting or shrinking) and maintain contain pH, respectively.
    b. Cells broken down in a Homogeniser which releases the organelles.
    c. Resultant fluid, homogenate, filtered to remove whole cells and debris.
    d. Homogenate spun in tubes in a Centrifuge. Nuclei sets at the bottom (heaviest organelle) as sediment. The reminisce known as supernatant which is removed and spun once more at a faster speed – Mitochondria sets at the bottom – sediment.
    11) TEM has the highest resolving power and magnification, as it uses a beam of electrons which has a short wavelength and so diffraction is considerably lower.
    a. TEM works by penetrating electrons through the specimen, some regions absorb the electrons appearing darker whilst other regions allow electrons to directly penetrate through, appearing brighter – onscreen image produced.
    b. Limitations: black and white, 2D imagine [EXPLAIN]
    c. Complex staining process – artefacts + specimen needs to be thin [EXPLAIN]
    ]

    Im adamant the LDL question is just simple diffusion as its Lipid soluble + Protiens dont bind to carrier protiens
    Offline

    2
    ReputationRep:
    There's a question on percentage change which is something like:
    [(81-70)/81] * 100% = 13.6% (3 s.f.)
    I guess
    Offline

    18
    ReputationRep:
    (Original post by Mvpmb)
    ]

    Im adamant the LDL question is just simple diffusion as its Lipid soluble + Protiens dont bind to carrier protiens
    Meh I put facilitated diffusion too like many others because it mentioned binding
    Offline

    2
    ReputationRep:
    Yo man, can you put down the # of marks for each question? Danke
    Offline

    1
    ReputationRep:
    (Original post by S.Ahmad)
    1)Pancreas and small intestine
    a.Maltase has a specific tertiary (3D) structure and so forms a unique active site, only which a complementary substrate can enter – Maltose. Forming Enzyme-substrate complexes.

    2)Ribosomes, golgi apparatus and mitochondria.
    a.Magnification of 2000 (1/100)/5x10^-6) = 2000.

    3)Lactose (disaccharide) hydrolysed into glucose and galactose which are both reducing sugars > whilst lactose remains undigested and so tastes less sweet.

    4)[Fish question]
    a.Conclusions:
    i.People who didn’t eat fish are more likely to suffer from asthma [data]
    ii.Can’t remember x2
    b.Test for lipids: grind the fish up, add ethanol and water and mix. A cloudy white colour/emulsion if form oils are present as they’re lipids.

    5)
    6)
    7)
    8)

    9)Antigens/bacteria which antibodies are required for.
    a.Facilitated diffusion, molecules bind onto the carrier proteins which causes them to change in shape and release to the opposite side – down the concentration gradient [high concentration to a lower concentration] from the blood – liver cells I think.

    10)Cell fractionation separates organelles in order of mass.
    a.Animals cells placed in cold, isotonic and buffered solution – reduce enzyme activity, prevent osmotic movement (cells bursting or shrinking) and maintain contain pH, respectively.
    b.Cells broken down in a Homogeniser which releases the organelles.
    c.Resultant fluid, homogenate, filtered to remove whole cells and debris.
    d.Homogenate spun in tubes in a Centrifuge. Nuclei sets at the bottom (heaviest organelle) as sediment. The reminisce known as supernatant which is removed and spun once more at a faster speed – Mitochondria sets at the bottom – sediment.

    11)TEM has the highest resolving power and magnification, as it uses a beam of electrons which has a short wavelength and so diffraction is considerably lower.
    a.TEM works by penetrating electrons through the specimen, some regions absorb the electrons appearing darker whilst other regions allow electrons to directly penetrate through, appearing brighter – onscreen image produced.
    b.Limitations: black and white, 2D imagine [EXPLAIN]
    c.Complex staining process – artefacts + specimen needs to be thin [EXPLAIN]
    9. a) was endocytosis : "LDL particles in the bloodstream bind to these extracellular LDL receptors. The clathrin-coated pits then form vesicles that are endocytosed into the cell." - wikipedia page for LDL
    Offline

    18
    ReputationRep:
    (Original post by AlexeiLipov)
    9. a) was endocytosis : "LDL particles in the bloodstream bind to these extracellular LDL receptors. The clathrin-coated pits then form vesicles that are endocytosed into the cell." - wikipedia page for LDL
    No one on this thread or the others have put endocytosis, I can't see them making that the answer like wtf are clarthin coated pills
    Offline

    1
    ReputationRep:
    Does anyone with a photographic memory remember the marks per question lol? I'd just like to see so I can roughly calculate by memory the amount of marks I may have achieved on this paper.
    Offline

    18
    ReputationRep:
    (Original post by Euthymic223)
    Does anyone with a photographic memory remember the marks per question lol? I'd just like to see so I can roughly calculate by memory the amount of marks I may have achieved on this paper.
    In order: 1,1,3,3,2,3,2,2 I can remember that lol
    Offline

    1
    ReputationRep:
    (Original post by Sacred Ground)
    No one on this thread or the others have put endocytosis, I can't see them making that the answer like wtf are clarthin coated pills
    The truth is the truth. It doesn't matter what everyone else says. I wrote down "diffusion because it was lipid soluble" so I'm angry too but hey it's endocytosis. The answer is the answer. Go on Google it, research it.
    Offline

    2
    ReputationRep:
    5, 5, 5 , 5 ,5, 8 10 7 10
    Offline

    18
    ReputationRep:
    (Original post by AlexeiLipov)
    The truth is the truth. It doesn't matter what everyone else says. I wrote down "diffusion because it was lipid soluble" so I'm angry too but hey it's endocytosis. The answer is the answer. Go on Google it, research it.
    I'd rather not research something we were taught for like 5 minutes and is included (apparently) in the exam which I believe isn't the answer

    P.s. ldl isn't soluble
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by AlexeiLipov)
    The truth is the truth. It doesn't matter what everyone else says. I wrote down "diffusion because it was lipid soluble" so I'm angry too but hey it's endocytosis. The answer is the answer. Go on Google it, research it.
    It's definitely Facilitated diffusion because of the carrier proteins.
    Offline

    1
    ReputationRep:
    (Original post by AlexeiLipov)
    The truth is the truth. It doesn't matter what everyone else says. I wrote down "diffusion because it was lipid soluble" so I'm angry too but hey it's endocytosis. The answer is the answer. Go on Google it, research it.
    Dude, the specific process of endocytosis isn't on the spec, so they'd never expect it on the markscheme. The exams are meant to be challenging, not impossible! :P (Endocytosis is probably right, we just don't need to know it in that much detail).
    Offline

    8
    ReputationRep:
    (Original post by S.Ahmad)
    It's definitely Facilitated diffusion because of the carrier proteins.
    Yes. We were taught on the spec that facilitated diffusion involves carrier proteins.
    Offline

    1
    ReputationRep:
    (Original post by alliah208)
    Dude, the specific process of endocytosis isn't on the spec, so they'd never expect it on the markscheme. The exams are meant to be challenging, not impossible! :P (Endocytosis is probably right, we just don't need to know it in that much detail).
    Endocytosis was on a past paper mark scheme on a question about transport of substances past cell surface membranes. Plus phagocytosis is just endocytosis and we learn about it in detail.. If endocytosis was not the mark scheme answer, what else could it be?
    Offline

    1
    ReputationRep:
    (Original post by S.Ahmad)
    It's definitely Facilitated diffusion because of the carrier proteins.
    Carrier proteins? It did not mention carrier proteins.. Receptors are not another word for carrier proteins
    Offline

    1
    ReputationRep:
    (Original post by AlexeiLipov)
    Endocytosis was on a past paper mark scheme on a question about transport of substances past cell surface membranes. Plus phagocytosis is just endocytosis and we learn about it in detail.. If endocytosis was not the mark scheme answer, what else could it be?
    Was it the sole answer, or was it just an option of a few ways to express it? I wrote facilitated diffusion because of the protein involved, but I could be wrong... I just find it difficult to believe that they would ask about a word that I've never heard of, and I know the spec inside out
    Offline

    2
    ReputationRep:
    For the third point about the beads question, do you think you could say there would be less lactose escaping through the process compared to the conventional example given in the question so you get 'purer' product with fewer lactose molecules?
    Offline

    12
    ReputationRep:
    The mark scheme always has endocytosis and exocytosis in brackets and they tend to put things we may know about about but dot really need to know in brackets.
    I think they'll accept anything that is valid tbh
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: June 14, 2016

2,628

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should predicted grades be removed from the uni application process

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.