Soni098
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Hi Guys,

I am trying to write notes for this part of the spec:

explain the adaptations of specialized cells in relation to the rate of transport across their internal and external membranes.

I am looking for this point in the 'AQA Biology 2nd edition textbook for A level year 1 and AS' and I can't seem to find it. Please let me know where it is, what it means, etc..
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EIBell
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Hello!
If you are referring to the book by Toole and Toole then I don't think that the book has a specific page, rather spread over other sections, like digestion.
My interpretation of the spec is that AQA are referring to organelles; intestinal epithelial cells are adapted to increase the rate of transport from the products of digestion into the blood by having many mitochondria for active transport energy from ATP for example.
I hope this helps but if you have teachers/tutors then they may be able to provide more clarity
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macpatgh-Sheldon
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Hi,

Here's an outline plan for you (you can derive such a plan for any Q by considering methodically every part of the body from head to toe [or a plant from flowers/leaves to roots OR in human biology think of all the physiological systems i.eCardiovascular system, lungs and breathing, digestive system, genito-urinary system, musculo-skeletal system, nervous system, endocrine system.

(Then think microscopic if relevant)

IN THE SAME ORDER:
1. Blood: RBCs - biconcave to increase surface area for O2 transport into cell + numerous (5 million per mm^3] and minute.
2. Lungs: alveoli - numerous + minute + extremely thin-walled squamous endothelial cells = large surface area for gas transport.
3. GI tract: microvilli on brush border -----> large surface area for efficient absorption of glucose, amino acids, fatty acids, vitamins. Presence of active transport proteins e.g. Na+, K+ ATPase, GLUT, etc. Numerous mitochondria for ATP to enable active transport.
4. Kidneys: Look up podocytes + PCT cells have microvilli + numerous mitochondria for active t.
5. Muscle: Highly branched sarcoplasmic reticulum (ER of myocyte = muscle cell) allows very fast transport of Ca++
6. Neurones: mitochondria enable fast movement of neurotransmitter along axon to terminal bouton to transport by exocytosis of vesicles containing ACh, NA, etc.
7. Hormones: e.g. beta cells in islets of Langerhans in pancreas have highly branched Golgi cisternae with numerous tiny vesicles that fuse with cell membrane to enable efficient transport of insulin out of cell into blood.

Easy peasy lemon squeezy yeah? Use your brain although Glen & Susan Toole are great authors.

Be safe!
M.
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Soni098
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(Original post by macpatgh-Sheldon)
Hi,

Here's an outline plan for you (you can derive such a plan for any Q by considering methodically every part of the body from head to toe [or a plant from flowers/leaves to roots OR in human biology think of all the physiological systems i.eCardiovascular system, lungs and breathing, digestive system, genito-urinary system, musculo-skeletal system, nervous system, endocrine system.

(Then think microscopic if relevant)

IN THE SAME ORDER:
1. Blood: RBCs - biconcave to increase surface area for O2 transport into cell + numerous (5 million per mm^3] and minute.
2. Lungs: alveoli - numerous + minute + extremely thin-walled squamous endothelial cells = large surface area for gas transport.
3. GI tract: microvilli on brush border -----> large surface area for efficient absorption of glucose, amino acids, fatty acids, vitamins. Presence of active transport proteins e.g. Na+, K+ ATPase, GLUT, etc. Numerous mitochondria for ATP to enable active transport.
4. Kidneys: Look up podocytes + PCT cells have microvilli + numerous mitochondria for active t.
5. Muscle: Highly branched sarcoplasmic reticulum (ER of myocyte = muscle cell) allows very fast transport of Ca++
6. Neurones: mitochondria enable fast movement of neurotransmitter along axon to terminal bouton to transport by exocytosis of vesicles containing ACh, NA, etc.
7. Hormones: e.g. beta cells in islets of Langerhans in pancreas have highly branched Golgi cisternae with numerous tiny vesicles that fuse with cell membrane to enable efficient transport of insulin out of cell into blood.

Easy peasy lemon squeezy yeah? Use your brain although Glen & Susan Toole are great authors.

Be safe!
M.
Thank you
Thinking in exam mode usually stops all of my logical thinking!
Thinking with my brain is something I must improve on!!!

Drop here!
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