ch 6 Flashcards
1
Q
elements of carbohydrates
A
CHO
2
Q
elements of fats
A
CHO
3
Q
elements of proteins
A
CHON
4
Q
function of carbohydrates [3]
A
- production of energy
-storage of energy as starch in plants and glycogen in animals
-cellulose form cell wall
5
Q
function of fats [4]
A
-production of energy
- storage of energy
-heat insulator
-fats around organs -> act as cushions as a shock absorbers
6
Q
function of proteins [5]
A
- growth and tissue repair
- form enzymes
- form hormones
- form antibodies
- form bones, muscles, hair, skin and haemoglobin
7
Q
sources of vitamin c [3]
A
orange, lemon and grape fruit
7
Q
components of balanced diet [7]
A
- carbohydrates, fats and proteins are needed in big amounts
-vitamins, fibres and minerals are needed in small amounts
-water
7
Q
vitamin D sources [3]
A
-egg yolk
-fish liver oil
-sunshine , formed under skin
7
Q
vitamin c functions [2]
A
- prevents scurvy (gum bleeding)
- prevents skin ulcers
8
Q
vitamin c deficiency symptoms
A
scurvy
skin ulcers
9
Q
vitamin D function
A
carry calcium from intestine to bones, to form strong bones
10
Q
vitamin D deficiency symptom
A
-soft bones
in children : rickets
in adults : osteomalacia
11
Q
calcium sources [2]
A
milk
milk products
12
Q
calcium functions [2]
A
form strong bones
form strong teeth
13
Q
calcium deficiency symptoms [2]
A
soft bones
soft teeth
14
Q
iron sources [4]
A
spinach
liver
red meat
egg yolk
15
Q
iron function
A
form haemoglobin inside the red blood cells which carry oxygen from lungs to all tissues
16
Q
iron deficiency symptom
A
anaemia :
-pale face
-easy fatigue
-shortness of breath
17
Q
sources for roughage [2]
A
-green leafy vegetables
-bran
18
Q
function of roughage
A
form a bulk in the large intestine which help with peristalsis
19
Q
deficiency symptoms of roughage [2]
A
constipation
cancer colon
20
Q
functions of water
A
-forms 80% of body
-solvent for all metabolic reactions
21
Q
state and explain 3 reactions in body that water acts as solvent for
A
- digestion, dissolves the nutrients in the digestive system
-excretion, dissolve the urea to form urine
-transport, forms 90% of plasma in blood
22
define the term balanced diet
it is the daily intake
of all types of food groups
in the right propotion
accoding to age, sex and activity
23
what happens if excess sugar in diet [2]
causes diabetes
causes tooth decay
24
what happens if excess salt in diet
high blood pressure
25
what happens if excess animal fats in diet [3]
heart attack
obesity
heart diseases
26
what happens if excess carbohydarates and fats in diet
obesity
27
how is weight affected if energy input > energy output ?
weight gain
28
how is weight affected if energy input < energy output ?
weight loss
29
describe the starch test
-in a clean, dry test tube add 2cc of starch solution followed by 1 drop of iodine (yellow brown)
-if starch is present the colour changes to blue black, if not present remains yellow brown
30
describe the reducing sugar test
-in a clean dry test tube take 2cc of the solution to be tested followed by an equal volume of blue benedict reagent. place in a water bath of hot water at 100 degrees for 2 mins. if reducing sugar is present orange red colour is formed and ppt is formed , if not remains blue
31
safety precautions for reducing sugar test [6]
-use test tube holder
-don't fill more than half the tube
-keep away from face
-tie long hair back
-wear gloves
-wear safety goggles
32
describe protein test
-in a clean dry test tube take 2cc of protein solution followed by 2cc of NaOH then add drops of CuSO4. if protein present, colour is purple, if not it remains blue
33
describe fat test
-in a clean dry test tube take 2cc of ethanol followed by few drops of fat, solution becomes clear then add 2cc of water. if there is fat, solution turns milky
34
describe vitamin c test
-in a clean dry test tube add 2cc of blue dye DCPIP then add 3 drops of vitamin c solution, turns colourless
35
what is chromosome made of
2 chromatids,, 2 DNA molecules
36
define gene
length of DNA which codes for a protein
37
what does one molecule of DNA consist of?
a double helix
38
how is a DNA strand formed?
joining nucleotides together by covalent bonds between the phosphates and sugars
39
describe complementary base pairing
when two polynucleotides, running in opposite directions are held together by hydrogen bonds between the bases. Adenine links with Thymine by 2 hydrogen bonds. Cytosine links with Guanine by three hydrogen bonds.
40
what is the backbone of DNA made of
alternating sugar-phosphate units
41
what does DNA stand for?
Deoxy-ribo- nucleic acid
42
what is DNA
it is the genetic material that is inhertited from parents and give them their characters
43
how many nitrogen bases code for 1 amino acid
3
44
how does DNA control cell functions ?
cell functions are controlled by proteins and these proteins are made of sequence of amino acids and this sequence of amino acids is determined by sequence of bases in DNA
45
how was classification of living organisms carried out traditionally?
using common features
46
how was classification of living organisms done using bases sequence in DNA?
biologists compare the base sequence of DNA in 2 different organisms form 2 different species. the more similair the base sequence, the more closely related the species to one another.
amino acid sequence is used in the same way
47
explain that classifications systems aim to reflect evolutionary relationships?
if a group of organisms of different species have same external features or same base sequence in DNA or same amino acid sequence in protein then we believe they are all coming from a common ancestor
-if their bases show more number of similarites then they have a more recent ancestor
48
state the steps of protein synthesis . [5]
- inside the nucleus DNA forms MRNA which carry information from the DNA to ribosome across the cytoplasm and DNA remains in nucleus
-this information is a copy of the base sequence in DNA
-MRNA leave the nucleus through nuclear pores to the cytoplasm and attaches to the ribosome
-ribosome takes amino acids from cytoplasm and join them together using energy to form protein
-amino acids are linked according to the base sequence in MRNA
49
define Diarrhoea
the loss of water faeces
50
effects of Diarrhoea [3]
-loss of water -> dehydration
-loss of salts-> weakness
-may lead to organ failure and death
51
treatment of Diarrhoea [3]
-oral re-hydration therapy, drinking water containing sugars and salt ions
-intra-venous solutions of salts, sugars directly to the blood
-antibiotics
52
causative organism of cholera
bacteria
53
methods of transmission of cholera [2]
-food born, eating food contaminated by human faeces containing cholera bacteria
-water born, drinking water contaminated by human faeces containing cholera bacteria
54
where is cholera most common?
places with bad hygiene conditions
55
how cholera causes diarrhoea? [6]
-cholera bacteria are ingested and multiply
-the bacteria attach to the wall of the alimentary canal
-the bacteria release toxins
-the toxins cause Cl ions to be released
-the release of the Cl ions causes water to move into the lumen by osmosis due to creation of a water potential gradient
-there is now a lot of water in the canal, and less Cl and water in blood
