organisation Flashcards
what is coronary heart disease:
-what can happen as a result
-when coronary arteries get blocked by fatty material build up,
-blood flow restricted as lumen gets smaller
-less oxygen reaches the heart muscle
-can cause a heart attack
what is a stent:
tube placed in an artery to expand it out
benefits of stents
-disadvantage
-quick surgery
-lasts a long time
-surgery always has risks (ie. infection, heart attack)
-possibility of developing a blood clot near stent (thrombosis)
what is a statin?
-what can it treat
-medication that alters the balance of cholesterol
-can treat cor hear dis, heart attacks, strokes by reducing amount of LDL in blood and increases good HDL
what is cholesterol?
-effects of LDL
-an essential lipid that body produces and needs to have in order to function properly
-too much of the bad (LDL) can cause fatty deposit build up in arteries and cause coronary heart disease
disadvantages of statins:
-usage
-side effects
-time
-long term usage (possible to forget)
-can have serious side effects (ie. kidney failure, memory loss)
-takes time to be effective
features of stomach:
-enzymes, prod?
-contracts muscular walls to push around and mix food
-prod. pepsin, a protease enzyme, breaks down proteins into amino acids
-prod HCl, kills bacteria, provides right environment for pepsin to work
role of small intestine:
-where digested food is absorbed into the blood
role of pancreas in digestion:
-prod most of the digestive enzymes
which r then released into the small intestine in the form of pancreatic juices
role of gallbladder:
-2 main functions
-where is it made (the substance in gallbladder)
secretes bile into small intestines
-bile: neutralizes stomach pH so that conditions are ideal for dig. enz. to function (bile is alkaline)
-emulsifies fat (lipids) (breaks it down to tiny droplets) , big surface area for dig. enz. to work on
-bile made in liver, stored in gbladd.
adaptations of sm. int.
-v, blood
-many villi, large SA, absorb. of food quicker
-villi, only 1 layer of surface cells, short diffusion pathway for nutrients
-very good blood supply, maintains conc. gradient
what happens in large intestine:
leftover material from s. int. pushed into it, excess h2o absorb.
-left with faeces, stored in rectum till removed
order of food journey in digestion
-mouth
-oesophagus (gullet)
-stomach
-small intestine (+pancreatic juices + bile)
-large intestine
-rectum
two main roles of digestion
-break down large food molecules into smaller molecules
-absorb these food molecules into body
what does amylase break down?
starch to maltose
which enzymes does the pancreas prod?
amylase, protease, lipase
levels of organisation: small to big
-organelles (eg. nucleus, mitochondria)
-cells
-tissues
-organs
-organ systems
-organisms
the definition of an organ
-group of different tissues
-working together to perform a common function
why incr. in temp is not good way to incr. react. rates
-requires lot of energy
-can increase non-useful reactions
-can damage cells
what is a catalyst
substance that speeds reaction, w/o being changed or used up
-enzyme: type of cat. (biological cat.)
factors effecting enzyme action
-pH
-temperature
in both cases, if two high or low, bonds holding the enzyme together will start to break apart,
changes active site shape
substrate no fit
said to be denatured
what does optimum temp mean
temp that gives the highest enzyme activity
importance of iron in diet
-important component in hemoglobin
-if not enough, could develop anemia, where not enough oxygen is able to get to tissues
importance of calcium
-needed for healthy teeth and bones
-else could develop rickets
need for fibre
helps food move through intestines properly
-stops diarrhea/ constipation
monomer for
-carbohydrates
-proteins
-lipids
-simple sugars (glucose, fructose)
-amino acids
what atoms are carbs, proteins, mainly
-C,H,O
-C,N,H,O
how do you start a food test
crush up the sample using mortar and pestle
-put crush in a beaker w/ distilled water & stir with glass rod till some dissolves
-filter out any solids with filter funnel paper
what is the test for sugars
-benedicts test
-only tests for reducing sugars
-put 5cm3 of food solution in test tube, put that in water bath heated to 75 C for 5 mins.
-if sugars present solution will turn green, yellow or brick red depending on conc.
what colour is benedicts solution
blue
test for starch
iodine test
-5cm3 of food solution, put few drops of iodine in, it is now brown colour
-shake, if starch present, solution = blue black
positive colour change for iodine test
blue black
positive colour change for benedicts test
green, yellow or brick red
test for proteins
-biuret test
-2cm3 of food solution, +2cm3 of biuret solution, turning it blue
-shake,
-if proteins present, will change to pink/ purple
positive colour change for biuret test
pink/purple
test for lipids
-sudan III
-5cm3 food solution (not filtered)
-add 3 drops of sudan sol.
-if lipids present, should get stained,
-as lipids separate from water, bright red layer at the top forms