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Urgent Help In Biology!!!!

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Plz anyone exlpain me da answers wats points needed to be wriitenbelow from syllabus for chapter enzymes transport in plants mammlian n gaseous exchange in Aslevel !!!!

Enzymes
(a) explain that enzymes are globular proteins that catalyse metabolic reactions;
(b) explain the mode of action of enzymes in terms of an active site, enzyme/substrate complex, lowering of
activation energy and enzyme specificity;
(c) follow the time course of an enzyme-catalysed reaction by measuring rates of formation of products
(for example, using catalase) or rates of disappearance of substrate (for example, using amylase);
(d) investigate and explain the effects of temperature, pH, enzyme concentration and substrate
concentration on the rate of enzyme-catalysed reactions, and explain these effects;
(e) explain the effects of competitive and non-competitive inhibitors on the rate of enzyme activity;


Transport
(a) explain the need for transport systems in multicellular plants and animals in terms of size and surface
area to volume ratios;
(b) define the term transpiration and explain that it is an inevitable consequence of gas exchange in plants;
(c) describe how to investigate experimentally the factors that affect transpiration rate;
(d) describe the distribution of xylem and phloem tissue in roots, stems and leaves of dicotyledonous
plants
(e) describe the structure of xylem vessel elements, sieve tube elements and companion cells and be
able to recognise these using the light microscope;
(f) relate the structure of xylem vessel elements, sieve tube elements and companion cells to their
functions;
(g) explain the movement of water between plant cells, and between them and their environment, in terms
of water potential (no calculations involving water potential will be set);
(h) describe the pathways and explain the mechanisms by which water is transported from soil to xylem and
from roots to leaves;
(i) describe how the leaves of xerophytic plants are adapted to reduce water loss by transpiration;
(j) explain translocation as an energy-requiring process transporting assimilates, especially sucrose,
between the leaves (sources) and other parts of the plant (sinks);
(k) explain the translocation of sucrose using the mass flow hypothesis;
(l) describe the structures of arteries, veins and capillaries and be able to recognise these vessels
using the light microscope;
(m) explain the relationship between the structure and function of arteries, veins and capillaries
(n) describe the structure of red blood cells, phagocytes and lymphocytes and explain the differences
between blood, tissue fluid and lymph;
(o) describe the role of haemoglobin in carrying oxygen and carbon dioxide;
(p) describe and explain the significance of the dissociation curves of adult oxyhaemoglobin at different
carbon dioxide levels (the Bohr effect);
(q) describe and explain the significance of the increase in the red blood cell count of humans at high altitude
(r) describe the external and internal structure of the mammalian heart;
(s) explain the differences in the thickness of the walls of the different chambers in terms of their functions;
(t) describe the mammalian circulatory system as a closed double circulation;
(u) describe the cardiac cycle;
(v) explain how heart action is initiated and controlled (reference should be made to the sinoatrial node, the
atrioventricular node and the Purkyne tissue);

Gaseous Exchange

(a) describe the structure of the human gas exchange system, including the microscopic structure of
the walls of the trachea, bronchioles and alveoli with their associated blood vessels;
(b) describe the distribution of cartilage, ciliated epithelium, goblet cells and smooth muscle in the
trachea, bronchi and bronchioles;
(c) describe the functions of cartilage, cilia, goblet cells, smooth muscle and elastic fibres in the gas
exchange system;
(d) describe the process of gas exchange between air in the alveoli and the blood;
(e) explain the terms tidal volume and vital capacity;
(f) describe the effects of tar and carcinogens in tobacco smoke on the gas exchange system;
(g) describe the signs and symptoms of chronic obstructive pulmonary disease (COPD), emphysema,
chronic bronchitis and lung cancer;
(h) describe the effects of nicotine and carbon monoxide on the cardiovascular system with reference to
atherosclerosis, coronary heart disease and strokes;
(i) evaluate the epidemiological and experimental evidence linking cigarette smoking to disease and early
death;
(j) discuss the problems of cardiovascular disease and the ways in which smoking may affect the risk of
developing cardiovascular disease

plz answers thesseee anyone of u i really need help !!!!
 
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i dont understand watz required what if they ask frm here wat wil i rite i want da main points for each one plzzz explain me...:(
 
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Filza, Could you do the zehmat of opening up your Mary Jones text book, Since you don't know anything in these chapters THEN go through s-cool.co.uk...
These topics are vast, they cannot be explained here =/
 
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bio Q2

enzymes have a complementary shape as that of substrate and the site of this shape is called active site!
energy of activation is the energy needed to reach the trasition state , enzymes lower this !
did u understand this one?
 
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go tru Cambridge bio a/as level revision guide by mary jones..!! u'll get 10% clear concept.! :D :D :D
 
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its not i read many times bt not getting main points wat to rite for each one...:(
 

XPFMember

XPRS Moderator
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then i think u shud take help from ur teacher...or better do pastpapers...it will let u know what and how to study :)
 
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then i must say u are wasting other's time. you dont want to do anything on ur own and want others to post in ur topic, stop this nonsense, you're irritating every time with new techniques !

P.s. Pray from Allah that you receive angel's help during exam, but for that you need to be 'non-irritative'
 
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