Cellulose is comprised of beta-glucose (1, 4) molecules, meaning that every other glucose molecule is inverted, forming a straight chain
Opposite –OH and-H groups are attracted to each other and so form hydrogen bonds as well
Overall making cellulose very strong, used in cell walls
Triglycerides
3fatty acids + glycerol = triglycerides
Produced by condensation reactions, i.e. removing water
Monounsaturated – one double bond
Polyunsaturated – more than one double bond
Stored under the skin around kidneys acts as an insulator
Phospholipids
2 fatty acids + phosphate = phospholipids
Phosphate end is hydrophilic, fatty acids hydrophobic and so phosphate end will dissolve.
Amino acids
Have a central carbon bonded to H, an amine and carboxylic group.
Last group is the R-group differs in each amino acid.
20 possibilities
Join to other amino acids by condensation reactions between –OH group on the carboxylic acid and the H on the amine group.
This is reversed by the addition of water, in hydrolysis
Bond formed is a peptide bond
Dipeptide formed – two amino acids
Polypeptide chains of man amino acids
Primary structure – loads of chains
Secondary – coil up to form, sheets or helixes by H-bonds
Tertiary – 3D forms more bonds between different chains and molecules.
Quaternary structure – bonding between different chains
(SHOW BOX OF BONDS)
Globular and fibrous molecules
Globular molecule shave hydrophilic ends pointing outwards and the hydrophobic inwards so they can dissolve or travel in the blood.
Different molecules added are called prosthetic groups (such as Haem)
Haemoglobin occurs 4 times and allows the oxidation of the iron present within it
Collagen an example of fibrous ones
(TABLE OF USES OF MINERALS)
Enzymes
Globular proteins i.e. complex 3D structure, with -philic and -phobic ends
Enzyme-substrate complex is formed
Reduce activation energy
Norm reaction is flattening curve
Enzyme Conc. Straight line
Substrate Conc. Increases then flattens (Vmax)
pH affects the bonds because amount of H+ ions therefore diff for each
Non competitive is when the inhibitor blocks the active site, distorts the enzyme structure, or end-product inhibition
Competitive is when there is competition for the active site i.e. antifreeze and ethanol.
Cell membrane/transport
Has a phospholipid bilayer – barrier for polar stuff and ions
Unsaturated ones form lose layers ‘cus they are bent, bacteria swap them in case of lower temps
Carbo branching chain on protein and lipid is glycoprotein and glycolipid respectively.
Cholesterol add structure stop exploding!
Glycol - allow bonding to other cells and water outside to hold cells together,
- they also have receptor cells for certain hormones or neurotransmitters, e.g. receptor for insulin in cells which produce sugar.
- Some glycoprotein are antigens for recognising other cells.
Protein channels perform facilitated diffusion
Water moves to lower potential
Plasmolysis forms plasmolysed cells (cell membrane pulled away from cell wall)
Active transport by carrier proteins opens gate on one side then shuts it, so only one way out, requires energy to keep gate shut
All of the facilitated and active transport has separate channels for each ion or molecule.
Endocytosis – phagocytosis bulk uptake of material by a vacuole
- pinocytosis bulk uptake liquid
Excotosis is the secreting of material out of the cell.
(INSERT PICTURE OF LUNG)
Blood with low o2 and high co2 is brought to the alveoli, and so diffusion occurs.
Lower water potential in the cell due to high concentration of ions
Therefore water comes passively
Ions actively
Genetics
DNA – deoxyribonucleic acid
DNA made by nucleotides, a phosphate group, pentose group and one of the nitrogen bases
CUTAG – cytosine uracil thymine adenine guanine
AT CG
RNA does not have T but U instead
The sugar is ribose or deoxyribose (being one more oxygen)
DNA polymerase adds new nucleotides during replication
*A gene is three a triplet code (one amino acid e.g. c-c-c)
mRNA transcribes code needed;
tRNA has an anticodon (an amino acid code) and the amino acid binds to the top of the anticodon (done by enzyme);
The mRNA goes to a ribosome and then translation occurs;
Peptide bonds formed catalysed by enzyme in ribosome peptidyl-tranferase;
tRNA leaves;
When stop codon reached mRNA leaves and chain is complete
*One polypeptide codes for one gene
Insulin mRNA is taken and is grown to form DNA for insulin; this is completed by reverse transcriptase the ends are then treated with guanine nucleotides
The bacteria (vector) is then treated to dissolve membrane and then centrifuged to separate out the plasmid (circular DNA)
Then cut open using a restriction enzyme
Then the ends are treated with cytosine
They then mix and using DNA ligase the T and G groups join
Plasmid placed inside a bacteria cell and fermented to produce insulin.
Factor VIII needed for blood clotting, made by modified hamster cells
Nuclear Division
Diploid is 2 chromosomes
Haploid is one chromosome
Humans have 23 pairs i.e. 46
Karotype is a picture that shows chromosomes
A chromatid has one DNA molecule
Gene controlling a particular characteristic is an allele (i.e. on both chromosomes)
Mitosis is cell division, meiosis is haploid production
The cell cycle – interphase, nuclear division and cell division
During interphase the cell is doing normal jobs and then replicates DNA when told and centrioles
Nuclear division is then done by mitosis
Early prophase – chromosomes coil up
Late prophase - centrioles move to poles, nucleolus and envelope disappear (go into vesicles)
Metaphase – spindle fibres form between centromeres and centrioles after they are lined up along the equator
Anaphase – they move to poles centromeres first
Telophase – stuff reappears, cytoplasm split by cytokinesis and the chromatids will uncoil to form DNA molecules
Benign doesn’t move about but malignant does
Habitat – organism crib
Niche – is job in an ecosystem
community – all the organisms living in one habitat
ecosystem – a relativity self-contained community of organisms
population – a group of organisms which live in the same place and can interbreed with each other
producer – photosynthetic organisms
consumer – eats above
tropic level – is level in chain on which the organisms sits(1st consumer, 2nd
10% from producer to first consumer
(NITROGEN CYCLE)
nitrogenase helps Rhizobium out
nitrosomonas and nitrobacter convert ammonia from piss into nitrite ions and then to nitrate ions (NO3-)
UNIT 2 – Health and Disease
Health and disease
Health is a person’s physical, mental and social condition
Disease is departure from good health for some reason
chronic is long-term
acute short term
Pandemic – over a large area
Epidemic – sudden spreading
Endemic – always there
(SHOW TABLE OF DIESEASE CATROGORIES)
Diet
(SHOW MINERAL TABLE)
RDA – recommended daily allowance
DRV – dietary reference values
Safe intake – indicates highest amount, before it gets toxic
eight essential amino acids – cannot be produced from other amino acids
fat not always problem, usually large supplies
protein energy malnutrition – kwashiorkor and marasmus
anorexia nervosa – wasting disease, caused by intentional weight loss and bad psychological state
xerophthalmia - lack in vitamin A(retinol) needed to prevent night blindness, and to produce retinoic acid which aid in growth and epithelial cells, also in deficiency affected immune system
Rickets and osteomalacia – calcium not deposited around bones or absorbed in liver, cause’s weak bones and susceptible to fracture
Gas exchange and exercise
Cartilage in trachea and bronchi - there to prevent them from collapsing in changing pressures, to keep them always open and to reduce air resistance, in the trachea they are c shaped rings, in bronchi they are irregular blocks
Smooth muscle in alveoli relax during exercise to allow more air intake
Alveoli contain elastic fibres which stretch depending on intake and then on recoil push equivalent air out
Goblet cell – produces mucus to trap crap from entering lungs
residual volume – volume left in lung after full exhalation
ventilation rate – amount of air in lungs for one minute
tidal volume x breathing rate
Stroke volume – volume of blood coming out each ventricle during each contraction
Cardiac output – amount pumped out during one minute
pulse rate – measured in beats per minute
Tidal volume – volume of air breathed in and then out in a single breath
tidal capacity – maximum breathed in and out
Systole – both ventricles contract
Systolic pressure – pressure at which the blood leaves the heart via the aorta
Diastolic pressure – minimum
hypertension – high diastolic and systolic pressures at rest, heart is working to hard
oxymyoglobin has higher oxygen affinity compared to oxyhameoglobin
on starting exercise – body produces adrenaline,
Arterioles constrict and vessels going to muscle dilate
Glucose is released from liver and fat from fat stores
Lactate in blood causes further constriction and dilation
Bronchioles also expand to allow more oxygen to enter
Oxygen deficit is built up, and the oxygen required after is known as the oxygen debt
(BENEFITS OF EXERCISE)
Smoking and disease
Chronic bronchitis - tar causes goblet cells to swell and secrete more mucus, and also kills cilia, as a result mucus builds up and bacteria grows within the stuff this causes coughs and narrow airways, chronic bronchitis a lot of phlegm is also produced(mucus mix inc. white blood cells)
Emphysema – inflammation of lungs causes phagocytes to move from capillaries and dissolve the elastic fibres covering the alveoli, causing the bronchioles to collapse on breathing tapping air in alveoli which can make them burst, this will then reduce the gas exchange surface
Chronic Obstructive Pulmonary disease – this is the overall condition.
low density lipoprotein transports cholesterol to damaged sites, high density removes it and takes it back to the liver.
Atherosclerosis – build up of atheroma (cholesterol, fibres dead muscle), forms plaques which restricts blood flow, if the blood then clots a thrombus forms, called a thrombosis can cause heart attacks or strokes, depending on artery
Coronary heart disease – angina pectoris – general shortage of blood
Heart attack(myocardial infraction) – blood clot
Heart failure - blockage of coronary artery heart beings to die and not pump efficiently
Pathogen – vibrio cholerae
Food borne, water-borne
Asia, Africa, Latin America
1-5 days
wall of intestine
severe diarrhoea, dehydration, weakness
microscopical analysis of faeces
Plasmodium falciparum, vivax, ovale, malariae
Insect vector, anopheles mosquito
Tropics and sub-tropics, Africa
Week to a year
Liver, red blood cells, brain
Fever, anaemia, nausea, headaches, muscle pain, shivering, sweating, enlarged spleen
microscopical analysis of blood
human immunodeficiency virus
worldwide, sub-Saharan Africa and south-east Asia
incubation of a few weeks, but no symptoms for up to 10 years for AIDS
brain cells, t lymphocytes and macrophages
HIV – flu like symptoms
AIDS – opportunistic infections including pneumonia, TB, cancer dementia
blood test
mycobacterium tuberculosis, M bovis
airborne droplets, via unpasteurised milk
worldwide
weeks-moths
Lungs – lymph nodes ,. bones and gut
Racking cough, coughing blood, chest pain, shortness of breath, fever, sweating, weight loss
microscopical analysis of sputum, or chest x-ray
Lymphocytes, phagocytes (neutrophils and macrophages)
Neutrophils can leave the blood stream and patrol tissues, don’t live long also clean up dead tissue
Macrophages also from bone marrow, in blood stream are moncytes then grow to macrophages, usually live in organs removing matter and if a disease is found dice the bacterium up to expose the antigen
When cells die they release histamine as well as toxins from pathogen
Neutrophils get attracted and bind to present antibodies resulting in endocytosis and excretion
B lymphocytes – mature in bone marrow then lymph nodes and spleen, can only make one antibody, they then make receptor proteins for the specific antigen and if contact is made, the B cell divides and turns in to plasma cells which produce the antibodies needed, extras are kept for memory
T lymphocytes – created in bone marrow mature in thymus gland, t helper cells release a hormone to stimulate B cell system, t killer cells will attach themselves to infected cell and inject H2O2 killing cell and pathogens inside, t cells also produce memory cells similar to B cells
natural active immunity - body fights it off
artificial active immunity – body fights dead parts, or antigens(a vaccine)
natural passive immunity – antibodies received from breast milk
artificial passive immunity – injected antibodies, antitoxins
antigenic drift - minor changes in antigen but still recognizable
antigenic shift – major change resulting in the need for another vaccine
(INSERT ANTIBODY PICTURE)
