Topic 1: Lifestyle, Health and Risk Part 2 Flashcards
what is Spearman’s rank and when is it used
a statistical test that looks at 2 data sets from the same sample
tells you if there’s a statistically significant correlation between them
always between -1 and 1
N = no. of individuals in sample
D = difference in rank of two measurements
theta = the sum of
what does an alternate hypothesis state
it states that there is a statistically significant correlation in your data
at what spearman’s rank value do you reject the null hypothesis and accept the alternate hypothesis
is the spearman’s rank is above the critical value
what is a cohort study
a longitudinal study where a participants are followed over time to see who develops a disease, people’s exposure to suspected risk factors are recorded during the study, to identify possible correlation
evaluate cohort studies
- studies can be very long and expensive
- invasive on the lives of patients
+ rare exposure; you can select specific conditions
+ it is the gold standard used for studying the association between a risk factor and the outcome
what is a case-control study
when a group of people with a specific disease is compared to a group without it
evaluate case-control studies
- they can be more prone to recall bias
- less adept at showing a causal relationship
+ they’re less time consuming and costly; useful when it’s difficult or expensive to obtain exposure data
+ useful when studying dynamic populations where follow-up can be difficult
what is recall bias
when the results of a study are skewed due to the participant’s memory
what are monosaccharides + examples
individual sugar monomers that carbohydrates are made from; general formula (CH2O)n
need to know = glucose, galactose, fructose
how do disaccharides form?
two monosaccharides react in a condensation reaction between two hydroxyl groups on a carbon 1 and carbon 4
forms: a disaccharide, water and a 1-4 glycosidic bond
what is hydrolysis
the breaking down of a a larger molecule through the addition of water
list 3 examples of disaccharides
sucrose = a glucose + fructose
the form that transports sugar around plants
maltose = a glucose + a glucose
produced when starch is broken down by amylase
lactose = ß galactose + glucose
the sugar found in milk
they are water soluble, but not as soluble as monosaccharides
how is a disaccharide converted into two monosaccharides?
a hydrolysis reaction
what is a polysaccharide
a saccharide formed from many monosaccharides linked by glycosidic bonds
what is starch
it is a storage molecule in plants
made from polysaccharides amylose and amylopectin
insoluble in water, so has no osmotic effect aka prevents cells from swelling up
what is amylose and what is it’s structure
a polysaccharide that forms starch
made of alpha glucose
1-4 glycosidic bonds
spiral/helical structure - very compact, a lot can be stored in a small place
what is amylopectin
a polysaccharide that forms starch
made of alpha glucose
1-4 and 1-6 glycosidic bonds
branched structure provides many terminal glucose molecules that can be rapidy hydrolysed for use during cellular respiration
what is glycogen (saccharides)
a polysaccharide
insoluble in water, it doesn’t cause cells to swell by osmosis
made of alpha glucose
compact so more glucose can be stored
physically large - cant diffuse through membranes§
has 1-4 and 1-6 glycosidic bonds; the branched structure makes hydrolysis easier (has even more branches than amylopectin)
what is cellulose
a polysaccharide
it is made from alternately inverted ß-glucose units
condensation reactions form 1,4-glycosidic bonds between glucoses
it forms perfectly straight chains
cellulose chains form H bond between each other
many cellulose molecules makes a microfibril
as it’s fibrous, cellulose is structurally important in plant cell walls
function of monosaccharides
function - to store energy within covalent bonds, breaking these bonds during respiration is how energy is released
also used as building blocks for polymers
they are water soluble for easy transport
lipid characteristics
they contain C,H,O - lower oxygen proportion than in carbohydrates
non- polar, insoluble in water but soluble in organic solvents
don’t form polymers
what are triglycerides
a type of lipid that make up most of the fat in humans and animals; made of 3 fatty acid chains and a glycerol backbone
the monomers are fatty acids and glycerol
how can fatty acids vary
- length of the hydrocarbon chain
- can be saturated or unstarurated
describe the formation of a triglyceride
they are formed through a condensation reaction
each OH group on the glycerol forms an ester bond with each COOH group on the fatty acid (glycerol’s H and the acid’s OH react)
3 water molecules are released because one glycerol and 3 fatty acids are used
what are the 2 main obesity indicators and how are they calculated
BMI: weight (kg)/height^2(m^2)
waist to hip ratio: waist circumference/hip circumference
- use the same units for both measurements
why do we have to use both BMI and WHR as obesity indicators?
BMI considers height but doesn’t differentiate between muscle or fat and doesn’t consider fat distribution
WHR may not work around excessively obese as after a certain point fat won’t be primarily around your waist, it is distributed around the whole body
what does a high WHR mean
a high WHR means more fat is around organs, this is visceral fat that increased CVD risk
what is an ‘energy budget’
energy taken in by an organism - energy used up by an organism
characteristics of glucose
- it’s a monosaccharide with 6 carbon atoms
- it’s structure makes it soluble so it can be transported easily
- it’s chemical bonds contain lots of energy as it is the main energy source for both animals and plants
describe the fatty acids of a triglyceride
it is a hydrocarbon chain that can vary in length (the glycerol doesn’t vary)
they are hydrophobic, making lipids insoluble in water
what do HDL’s do
mainly protein
transport cholesterol from body tissues -> liver, where it’s excreted or recycled
they reduce total blood cholesterol when the level gets too high
what are LDLs
mainly lipid
transport cholesterol from the liver to the blood where it will circulate until cells need it
they increase total blood cholesterol when the level gets too low
devise an experiment to test for the amount of vitamin C in food
- make up Vitamin C solutions; 0, 0.2, 0.4, 0.6, 0.8, 1.0 mol
- use a measuring cylinder to measure out 1cm3 of 1% DCPIP into a test tube
- add one of the solutions to the DCPIP drop by drop, using a graduated pipette
- shake for a set length of time after adding each Vit C drop (use a stopwatch)
- record the volume of vitamin C added when the solution turns colourless
- repeat a total of 3 times for each solution and find the mean
- draw a calibration curve as a line of best fit on a graph using these results
you can then use the curve to test an unkown solution; find the DCPIP volume needed to decolourise then read across and down to find the concentartion
what types of triglycerides form what types of lipoproteins
saturated triglyceride -> LDL
unsaturated triglyceride -> HDL
why are terminal glucose molecules good
rapid hydrolysis
where can DNA be found in a cell
the nucleus and mitochondria
where can RNA be found in a cell
the cytoplasm, nucleus and ribosome
