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Tuesday 29 October 2013

Miss Timms Half Term Heart Questions

Task: 
a) answer the following questions (just write down the question number and your answer- unless you want to print out the questions). 

b) next to the question number can you write whether you think it is an AO1, AO2 or AO3 question.

AO1- knowledge
AO2- application of knowledge and how science works
AO3- how science work


Questions:

CHD-

Smoking as a risk factor:

Smoking is a risk factor associated with coronary heart disease. Smoking is known to raise the concentration of fibrinogen in the blood, promote the aggregation of platelets and reduce the ability of arteries to dilate.
Use this information to:
(a)        explain the effect of smoking on blood pressure;
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(2)
(b)        explain how smoking might lead to the formation of a blood clot.
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(3)
(Total 5 marks)

Cholesterol as a risk factor:
Coronary heart disease is a major cause of death in the western world.
(a)        The diagram shows an external view of a human heart with a blood clot in one of the main coronary arteries.




(i)            Shade, on the diagram, the area of heart muscle which is likely to receive a reduced supply of blood because of the blood clot.
(1)
(ii)            Explain why a blood clot in a coronary artery is likely to result in a heart attack.
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(3)
(b)        Three important risk factors associated with coronary heart disease are cigarette smoking, high blood pressure and a high plasma cholesterol level. Explain how each of the three factors increases the risk of heart disease
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(6)




Atheroma:
(a)        What is atheroma?
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(2)
(b)        Describe how atheroma can lead to an aneurysm.
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(2)
(Total 4 marks)


Cardiac cycle-


Pressure changes in the cardiac cycle:
(a)        During the cardiac cycle the heart fills with blood and then the ventricles contract. The table gives the filling time and the contraction time at different heart rates.
Heart rate/beats
per minute
Filling time/seconds
Contraction
time/seconds
39.7
0.37
1.14
49.6
0.38
0.83
71.4
0.38
0.46
81.1
0.38
0.36
87.0
0.39
0.30
(i)            Give two conclusions that can be drawn from the figures in the table.
1 ........................................................................................................................
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2 ........................................................................................................................
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(2)
(ii)            Explain how you would use the figures in the table to calculate the contraction time at a heart rate of 60 beats per minute.
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(2)
(iii)            What additional information would you need in order to find the cardiac output at a particular heart rate?
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(1)

Monday 21 October 2013

Term 1 Assessment Mark Scheme- Miss Hadgkiss

Mark Scheme for Term 1 Assessment

 
1. (a) Amylase;
(Starch) to maltose:
Maltase;
Maltose to glucose;
Hydrolysis;
(Of) glycosidic bond;

Q Do not penalise incorrect site for digestion or incorrect site of

enzyme production.
 
2. (a) (i) Increase to 30 °C/31 °C and then decreases / optimum or max

rate at 30 °C/31 °C;


Accept: peak at 30 °C/31 °C



(ii) 1. Enzyme denatured / hydrogen bonds/bonds holding tertiary

structure broken / tertiary structure changed;

2. Change in shape of active site (of enzymes);

3. Substrate / protein no longer fits / binds (into active site) / few or no ES

complexes;

4. More enzyme (molecules) denatured as temperature increased;


1. Reject: Peptide bonds broken

Denatures active site = 2 marks for mp 1 and 2

2. Q Only allow second point if active site is used correctly

Accept: active site no longer complementary

3. Accept: Substrate cannot bind to enzyme



3 max



(b) (i) Use buffer / test pH (at end/ at intervals);


Accept a method of measuring pH.

Reject litmus.

 
(ii) (30 °C/31 °C) Maximum rate / optimum temperature;


Accept other valid answers e.g. temp below

30 °C as enzyme not denatured.



1



(iii) Works best at pH 6 / at higher pH activity decreases;


Accept converse

Insufficient: pH 6 had largest clear area



1
3. (a) (i) Active site/enzyme not complementary;



Active site changes (shape)/is flexible;
(Change in enzyme allows) substrate to fit/E-S complex to form;
 
Active site becomes complementary/wraps around substrate = 2
marks
For mark point 2. allow ‘binding site’ but not ‘enzyme’
For mark point 2. can only have enzyme changes (shape) if active
site has been mentioned earlier
Final mark point must have context
Reject: active site on substrate for second marking point only
Accept: diagrams only if suitably labelled or annotated
 
 
2 max
 
 
 
(ii) Active site does not change (shape)/is fixed (shape)/is rigid/does
not wrap around substrate/(already) fits the substrate/is
complementary (before binding);
 
Assume that ‘it’ refers to lock and key
 
 
 
1
 
 
 
Page 9 of 12
 
 
(b) Similar structure/shape (to PABA)/both complementary;
Competes for/binds to active site/competitive inhibitor;
Less PABA binds/less E-S complexes;
 
OR
 
 
 
 
Specific reference to different structure/shape (to PABA)
using the diagram;
Binds to position other than active site/binds to allosteric
site/binds to inhibitor site/non-competitive inhibitor;
Changes the active site so substrate cannot bind/less PABA
binds/less E-S complexes;
 
Q Reject: same structure/shape
Note: competitive inhibitor binds to active site = 1 mark (same
mark point)
Assume that ‘it’ refers to sulfanilamide
Accept: PABA/substrate cannot bind
Neutral: less product produced as in question stem
Neutral: different structure/shape to PABA
Reject: active site on substrate for second marking point only
 
 
3 max
 
 
[6]
4. (a) (i) Increases then plateaus/constant/steady/rate does not change;
Neutral: ‘peaks’/‘reaches a maximum’/‘stops increasing’/‘no effect’
instead of ‘plateaus’
Reject: rate decreases/reaction stops
 
 
Correct reference. to 27/28 units;
e.g. increases up to/plateaus at 27/28
 
2
 
 
 
(ii) Substrate concentration/amount of substrate;
As substrate concentration increases, rate increases/positive
correlation (between rate and substrate concentration);
 
2
 
 
 
(iii) All active sites occupied/saturated/enzyme limiting (rate of
reaction)/maximum number of E-S complexes;
 
Reject: enzymes used up
Reject: substrate limits rate of reaction
Neutral: substrate no longer limits the reaction
Neutral: reference to temperature
 
 
1
 
 
 
Page 10 of 12
 
 
(b) Curve is lower and plateaus at a higher substrate concentration
(it must also start at zero);
 
Accept: curve lower and joins existing curve at final point (with no
plateau)
Reject: if curve plateaus before original
Reject: if curve plateaus lower than original
 
 
1
 
 
 
(c) (i) Methotrexate/drug is a similar shape/structure to substrate;
 
 
Q Reject: same structure/shape
 
Binds to/fits/is complementary to active site;
 
 
Q Reject: reacts with active site
 
Less substrate binds/less enzyme-substrate complexes formed;
 
 
Accept: substrate cannot bind/enzyme-substrate complex not
formed
 
 
2 max
 
 
 
(ii) Methotrexate/drug is only similar shape to specific substrate/
only fits this active site;
 
Assume that ‘it’ refers to the drug
 
 
OR
Methotrexate/drug is a different shape to other substrates/will
not fit other active sites;
 
1
 
 
[9]
5. (a) C
12
 
 
; H

22
 
 
O
 
 
11
 
 
;
 
 
2
 
 
 
(b) (i) heat with Benedict’s;
yellow/brown/orange/red;
 
2
 
 
 
(ii) (yes)
 
 
(may appear on second line)
 
 
 
more precipitate in sample B;
both sugars are reducing sugars/ give a positive test;
 
 
2
 
 

















































































 
 








[6]

Sunday 20 October 2013

Lactose Intolerance- Miss Hadgkiss

Half Term Tasks


1). Research racial incidence of lactose intolerance.
2). What are the tests for lactose intolerance and how are they interpreted. (p.55 Hodder may help)
3). Answer the question below.

Lactose intolerance website links.

http://www.nationalstemcentre.org.uk/elibrary/resource/912/converting-milk-products-using-lactase

http://au.lifestyle.yahoo.com/health/reference/article/-/8651743/lactose-intolerance/

http://www.netdoctor.co.uk/digestivehealth/lactoseintolerance.html

http://www.nlm.nih.gov/medlineplus/ency/article/003500.html

Q1. Lactose is present in milk. It is broken down by lactase into glucose and galactose. This is



shown in the equation.

(a) Name the type of reaction shown in the equation.

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(1)
 
 
(b) The molecular formula of galactose is C6H12O6. What is the molecular formula of lactose?



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(2)
 
 
(c) Doctors use a lactose tolerance test to find out if a person is lactose intolerant. In this test,

the person is given a solution of lactose to drink. Blood glucose concentration is then

measured over the next two hours.

A lactose tolerance test was carried out on a healthy man who was lactose tolerant, and

on a man who was lactose intolerant. The results for the first hour are shown in the table.

(i) The blood glucose concentration changed in the healthy man after he had taken the

test. Describe how.

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(ii) Explain the results for the lactose intolerant man.

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Tuesday 15 October 2013

CHD websites and resources

http://www.nhlbi.nih.gov/health/health-topics/topics/cad/
http://www.bhf.org.uk/heart-health/conditions/coronary-heart-disease.aspx

online biology text book:
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter44/

Friday 18th October- Miss Timms

We will be looking at coronary heart disease and atherosclerosis.

Can you bring in all your heart notes so far (classwork and independent work)

Can you also bring in your assessment tracking sheet to add details from the presentation questions


Thanks
Miss Timms

Monday 7 October 2013

To bring/ or remember for Tuesday 15th Oct Miss Timms

Presentation revision for questions on your researched topic
4 people doing their presentations- Jana, Isobel, Owen and George

Homework from last week:
CO calculations
Journey of a RBC linked to cardiac cycle
Heart structures table

For those who haven't already given these in:
TV and heart disease questions
Assessment questions plus model answers

Control of the cardiac cycle questions- Miss Timms


The cardiac cycle is controlled by the sinoatrial node (SAN) and the atrioventricular node (AVN). Describe how.

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(5)

Saturday 5 October 2013

Monday 7th Oct- Miss Timms 124B1

Can you all please bring in your assessment questions with model answers and the television and heart disease questions.

Also bring in your cardiac cycle diagrams and notes to add details about the control of the cardiac cycle.

Thanks
Miss Timms


Cardiac cycle- homework Miss Timms Friday 4th Oct


Cardiac output calculations
If the stroke volume has decreased to 40ml and the heart rate remains at 72bpm- what will the cardiac output be? What will be the effect of this? Why might the stroke volume decrease?
If the heart rate increases to 100bpm and the stroke volume stays at 75ml-what will the cardiac output be? What will be the effect of this on the individual? Why might the heart rate increase?
Write the journey of a red blood cell though the heart- the sequence of blood vessels and chambers. Use all the keywords and parts of the heart structure in your answer. Can do it as a flow diagram with animations, a storyboard or as written prose (story/ poem/ narrative).

Thursday 3 October 2013

Cardiac cycle exam questions- Miss Timms Friday 4th Oct


Pressure changes in the cardiac cycle:
(a) During the cardiac cycle the heart fills with blood and then the ventricles contract. The table gives the filling time and the contraction time at different heart rates.
Heart rate/beats
per minute
Filling time/seconds
Contraction
time/seconds
39.7
0.37
1.14
49.6
0.38
0.83
71.4
0.38
0.46
81.1
0.38
0.36
87.0
0.39
0.30

(i)            Give two conclusions that can be drawn from the figures in the table.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
...........................................................................................................................
(2)

(ii)            Explain how you would use the figures in the table to calculate the contraction time at a heart rate of 60 beats per minute.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)

(iii)            What additional information would you need in order to find the cardiac output at a particular heart rate?
...........................................................................................................................
(1)



Tuesday 1 October 2013

Enzyme Animation Link + Quiz!

Enzyme animation

Use the above link to revise and test your knowledge on enzymes

Miss Timms homework 2!

2. complete model answers for the questions you got wrong on the assessment

Remember next week that there will be a presentation lesson (some selected to be presented) and you will all have to complete questions on your chosen topic.

:)

Heart structure- Miss Timms

LO:

1. What is the appearance of the heart and its associated blood vessels?
2. Why is the heart made up of two adjacent pumps?
3. How is the structure of the heart related to its function?

Homework:
1.  structure and function table
create a table of the various structures in the heart and link their structure to their function.

                                                   structure                                      function


Aorta

L. atria

R. atria

L. ventricle

R. ventricle

Vena cava

Pulmonary artery

Pulmonary vein

Coronary arteries


blog address

http://asbiologyka.blogspot.co.uk/