Diet & Food production.

  • Created by: rachel
  • Created on: 21-03-13 12:56
Define the term balanced diet.
A diet that contains all the nutrients required for health & growth in the correct proportions.
1 of 22
Explain how consumption of an unbalanced diet can lead to malnutrition.
Malnutrition caused by unbalanced diet. Obesity caused by consuming too much energy & excess energy deposited as fat in adipose tissue. Obesity is condition where excess fat deposition impairs health & usually defined when person has BMI over 30.
2 of 22
Discuss the possible links between diet & coronary heart disease.
Excess salt in diet decreases Ψ of the blood -> more water is held in the blood & BP decreases. Can lead to hypertension, which can damage inner lining of arteries, which is one of the early steps in process of atherosclerosis. Sat fat harmful.
3 of 22
Discuss the possible effects of a high blood cholesterol level on the heart & circulatory system with reference to high-density lipoproteins (HDL).
Carry cholesterol from tissues to liver (there are receptors for HDLs on liver cells). HDLs lower blood cholesterol so reduce deposition of fats & cholesterol & so decrease the formation & risk of atheromas.
4 of 22
Discuss the possible effects of a high blood cholesterol level on the heart & circulatory system with reference to low-density lipoproteins (LDL).
LDLs carry cholesterol from the liver to the cells & there are receptors for LDLs on the cells. LDLs raise blood cholesterol. Therefore they increase deposition of fats & cholesterol under the endothelium of an artery & form atheromas.
5 of 22
What do saturated fats do to he activity of LDL receptors?
Saturated fats < the activity of LDL receptors, so as the blood LDL conc rises, less is removed from the blood. This results in higher concentrations of LDL in the blood, which are then deposited on artery walls.
6 of 22
Explain that humans depend on plants for food as they are the basis of all food chains.
Photosynthesise (light energy -> chemical energy). Absorb nutrients from soil & make other bio mol. Herbivores make use of these biological molecules when they eat & digest food. Humans eat plants & herbivores , gaining nutrients directl & indirectly
7 of 22
Outline how selective breeding is used to produce crop plants with high yields, disease resistance & pest resistance.
2 plants with desired characteristics reproduce. Offspring are sorted carefully to select those with best combination of characteristics & only those offspring are allowed to reproduce. Continues for many generations & required characteristics exagg.
8 of 22
Outline how selective breeding is used to produce domestic animals with high productivity.
2 animal with desired characteristics reproduce. Offspring are sorted carefully to select those with best combination of characteristics & only those offspring are allowed to reproduce. Continues for many generations & required characteristics exagg.
9 of 22
Describe the disadvantages of selective breeding being used to produce domestic animals with high productivity.
Growth may be too rapid. Possibility of > susceptibility to disease. Can cause inbreeding. Reduces genetic variation.
10 of 22
Describe the use of fertilisers with plants & how they can increase food production.
Fertilisers replace the minerals in the soil which may have been removed by previous crops. They contain nitrate, phosphate & potassium. They increase the rate of growth & therefore the yield.
11 of 22
Describe the use of pesticides with plants & how they can increase food production.
Pesticides kill organisms that cause diseases in crops. These organisms would reduce yield or kill the crop. Many crops are sprayed with fungicides to reduce fungal growth in leaves or roots. Sheep are dipped to kill ticks.
12 of 22
Describe the use of antibiotics with animals & how this can increase food production.
infected animals can be treated with antibiotics to reduce the spread amongst animals that are intensively farmed in close proximity to each other. Such diseases could reduce the growth performance of the animals & may impair reproduction.
13 of 22
Describe the advantages of using microorganisms to make food for human consumption.
Production of protein is faster than that of animal/plant protein. Production can be > or < according to demand. No animal welfare issues. Good source of protein for Veg. Single cell protein production could be combined with removal of waste products
14 of 22
Describe the disadvantages of using microorganisms to make food for human consumption.
People won't want to eat fungal protein (been grown on waste). Protein must be purified due to contamination. Doesn't have taste/texture of traditional protein. Microorganisms grown in huge fermenters & need to be isolated from material grown on.
15 of 22
When is food spoilage caused?
When bacteria reproduce & secrete enzymes to digest protein to amino acids, the triglycerides to fatty acids & starch to glucose. The bacteria also produce toxins & waste products that causes changes in appearance, smell, texture & taste of food.
16 of 22
How can salting be used to prevent food spoilage by microorganisms?
Bacteria die due to lack of water as water leaves them by osmosis because of a lower water potential outside the cell.
17 of 22
How can adding sugar be used to prevent food spoilage by microorganisms?
Bacteria die due to lack of water as water leaves them by osmosis because of a lower water potential outside the cell.
18 of 22
How can pickling be used to prevent food spoilage by microorganisms?
Acid pH denatures any microorganisms proteins & therefore enzymes. This substrate no longer fits the active site.
19 of 22
How can freezing be used to prevent food spoilage by microorganisms?
Bacteria reproduce slower -> fewer bacteria will be present -> less toxins & waste are produced & less enzymes are secreted. Enzyme action will be slower as the substrate & enzymes have less kinetic energy & fewer enzyme-substrate complexes formed.
20 of 22
How can heat treatments be used to prevent food spoilage by microorganisms?
They denature any microorganisms proteins & therefore enzymes. The substrate no longer fits the active site.
21 of 22
How can irradiation be used to prevent food spoilage by microorganisms?
Kills organisms by disrupting their DNA structure causing mutations.
22 of 22

Other cards in this set

Card 2

Front

Explain how consumption of an unbalanced diet can lead to malnutrition.

Back

Malnutrition caused by unbalanced diet. Obesity caused by consuming too much energy & excess energy deposited as fat in adipose tissue. Obesity is condition where excess fat deposition impairs health & usually defined when person has BMI over 30.

Card 3

Front

Discuss the possible links between diet & coronary heart disease.

Back

Preview of the front of card 3

Card 4

Front

Discuss the possible effects of a high blood cholesterol level on the heart & circulatory system with reference to high-density lipoproteins (HDL).

Back

Preview of the front of card 4

Card 5

Front

Discuss the possible effects of a high blood cholesterol level on the heart & circulatory system with reference to low-density lipoproteins (LDL).

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Health, illness and disease resources »