Term
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Definition
*enzymes are biological catalysts they speed up reactions
*they are large proteins each with own shape which has area where other molecules can fit called active site
*high temp changes enzyme shape and it is denatured (destroyed)
*catalyse build up of small to large molecules or vice versa
*they lower the amount of energy needed |
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Term
| factors affecting enzyme action |
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Definition
faster when warmer as molecules move round faster and quickly collide
if too hot enzyme stops working
work best in alkaline or acidic ph. If ph wrong then shape is changed and enzyme denatured |
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Term
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Definition
respiration equation
glucose + oxygen = carbon dioxide +water
mostly takes place in mitochondia
energy released used for
*build larger molecules
*enable muscle contraction
*maintain body temp
*build sugars, nitrates and other nutrients into amino acids and then proteins |
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Term
enzymes in digestion
Amylase |
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Definition
*amylase prduced by salivary glands, pancreas and small intestine.
*catalyses digestion of starch into sugars in mouth and small intestine |
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Term
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Definition
*produced in stomach, pancreas and small intestine
*catayses breakdown of protein into amino acids in stomach and small intestine |
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Term
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Definition
*produced in pancreas and small intestine
*catalyses breakdown of lipids (fats and oils) to fatty acids and glycerol |
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Term
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Definition
protease works best in acid conditions
glands in stomach wall produce hydrochloric acid
Amylase and lipase work in small intestine best in slightly alkaline condition
Bile made in liver (stored in gall bladder) squirted in small intestine to neutralise stomach acid to make slightly alkaline |
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Term
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Definition
*biological washing powders contain enzymes to digest food stains, work at lower temps
*protease in baby food to predigest some proteins
*isomerease converts glucose to fructose which is much sweeter so less is needed
*carbohydrases to convert starch into sugar syrup for use in foods |
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Term
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Definition
process in body to maintain constant internal environment
*must remove waste products produced from chemical reactions
eg carbon dioxide excreted through lungs
eg unused amino acids converted into urea in liver excreted by kidneys in urine stored in bladder
*water and ion content must be controlled |
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Term
controlling temperature
Fall in temperature |
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Definition
if temp falls blood vessels near surface of skin constrict and less blood flows through skin capillaries and less heat radiated
we shiver -muscles contract quickly which requires respiration which releases heat so we don't get cold |
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Term
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Definition
blood vessels near surface of skin dilate allowing more blood to flow through skin capillaries and heat is lost by radiation
sweat glands produce sweat which evaporates from skins surface and we cool down |
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Term
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Definition
pancreas controls and monitors level of sugar in blood
*too much sugar then pancreas produces the hormone insulin and excess sugar stored in liver as glycogen
If insulin not produced then diabetes
diabetes can be controlled by diet or insulin injections |
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Term
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Definition
*cell division is necessary for growth and repair
*mitosis is when 2 identical cells are produced from the original cell
*A copy of each chromosome is made before cell division. |
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Term
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Definition
*unspecialised but can differentiate.
*found in embryo and adult bone marrow but those in marrow limit the amount of specialised cells that can be developed from them
*research done on embryonic stem cells are those from aborted embyos and spare embryos from fertility treatment -ethical issues as argued life is destroyed for stem cell research |
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Term
| cell division and sexual reproduction |
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Definition
*cells in reproductive organs (testes/ovaries) divise to form sex cells called gametes
*before division a copy of chromosome made then cell divides twice this is called meiosis
*each gamete has 1 chromosome from original pair and are all different |
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Term
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Definition
| sexual reproduction results in variation as gametes from each parent fuse, so half info comes from mother and half from father |
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Term
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Definition
gregor mendel was a monk who worked out how characteristics were inherited
genes are short lengths of DNA (deoxyribonucleic) which make up chromosomes and control our characteristics
* genes code for combinations of specific amino acids to make protein |
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Term
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Definition
humans have 23 pairs of chromosomes.
1 pair are sex chromosomes
XX females
XY males
*genes controlling same characteristics are alleles
If allele masks effect it is dominant
If allele is masked it is recessive |
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Term
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Definition
disorder affecting nervous system
caused by dominant allele
can be inherited even if only 1 parent has the disease |
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Term
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Definition
disorder of cell membranes
caused by recessive allele so parents may be carriers
both parents carriers or have disease for child to get |
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