applied science

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Cards (44)

what is a hypothesis? give example
a hypothesis is a idea which you can test with practical experiments for example if we increase the temperature then the rate of reaction will increase
what is a null hypothesis? give example
a null hypothesis is when you say that there is no relationship for example the pH of the soil does not affect the rate of photosynthesis
what do you need to take into account to choose appropriate equipment?
what is it for ? how many is needed? how precise does it have to be? what size does it have to be? (for, how many, precision, size)
what do you need to take into account to choose appropriate techniques?
what are your investigating? what methods are you using? do you have the equipment available? do you have enough time? do you have the skills and knowledge? (what, method, availability, time, skills and knowledge)
what is standard operating procedure (SOP)? give examples
it is the standard way to carry out an experiment to ensure reliable accurate results for example titration, disposal of waste or preparing solutions)
what is qualitative data?
Qualitative data is differences you can see for example colour or if bubbles were produced or not
what is quantitative data?
quantitative data is numerical for example measurements
give examples of a hazard. (what is the risk? what will happen? how will you minimise?
chemical spill can give chemical burns if not careful and to minimise chances you should place chemicals int he middle of the table and out of the way as well as wearing goggles or face shields. if skin is contacted with he chemical wash skin with running cold water
what is a independent variable?
an independent variable is something you change in the experiment for example the the height ball is dropped at or what type of ball it is
what is a dependent variable?
a dependent variable is what you are investigating and measuring during a an investigation
what is a controlled variable?
a controlled variable is what you keep constant during the investigation for example the height the ball is dropped from or type of ball
how do you write a method?
say what your independent ,dependent and controlled variables are , measurements and how you will take them, say if you are going to take any repeats
what is an anomalous?
irregular or very different
how do you collect data?
using a logical manner, using clear headings, units, repeated results, averages and point out any anomalous
what do u need to ensure in a graph?
right axis, units ,headings, title and line of best fit
how do you get the rate of reaction 
at a certain time draw a point on the graph and draw a tangent at that point on the graph. To work out the gradient is change in y value and x value
what is primary data ?
primary data is what you have gathered yourself through the experiments and investigations for example hair and eye colour
what is secondary data?
secondary data is data that is given to you
what is mean ?
mean is the average value and to work it out you add and divide by how many values there are
what is standard deviation ?
standard deviation tells us how spread of the results, how close the results are to the mean value. The smaller the deviation the less uncertainty there is in the results
what is chi-squared test?
it is a test which can be used to see if the difference between observed and expected numbers is significant or due to chance
what is a T- test?
A T- test compares 2 sets of data
what is error bars?
error bars are drawn on graphs to show uncertainty in the measurements. Error bars are usually the size of one standard deviation above the mean value. error bars can also be drawn to represent the range of repeated readings taken for each plotted point
what is correlation analysis
correlation analysis is finding out whether a relationship exists between variables and then determining the magnitude and action of that relationship. A line of best fit on a graph can show whether there is no correlation or a positive or negative correlation between variables.
how do you know there is no correlation?
when there is no correlation there is no clear pattern in your data
how do you know there is a positive correlation?
you would know if an increase in one variable (x-axis), causes an increase on the other (y-axis)
how do you know there is a negative correlation?
if an increase in one variable (x-axis) causes a decrease in the other (y-axis)
how do you know if it is a strong positive correlation?
if a correlation is strong most of the plotted data points are close to the line of best fit
putting kilo in front of a unit increases the size by 1000
what is a systematic error?
it is something wrong with the system either the method or equipment and will effect every reading
what is a random error?
are unpredictable caused by unpredictable changes in the experiment and will effect the precision , can be minimised by taking multiple readings and taking an average
what is repeatability? 
an experiment is repeatable if the same person carries it out under the same conditions and gets very similar results
what is reproducibility?
an experiment is repeatable if somebody else carries out the same experiment using different equipment and gets similar results
how do you work out the percentage error of measuring equipment?
measured - actual / actual x100
what is an enzyme?
an enzyme is a protein molecule that acts as a catalyst in a biomedical reaction. ( the interaction of two or more substances to produce another substance)
what are amino acids?
amino acids are building blocks of proteins
what are proteins?
proteins are macromolecular polypeptides—i.e very large molecules (macromolecules) composed of many peptide-bonded amino acids. proteins catalyse reactions ( enzymes), they help bind cells into tissues, they can be antibodies which protect us from pathogens they transport materials, they can carry chemical messages ( hormones) and they control the activity of genes
what is the structure of amino acids?
in an amino acid there is a central (alpha) carbon with four chemical groups attached to it:
a hydrogen atom
a amino group
a carboxyl group
a variable R group (side chain) there are 20 different side chains
how do amino acids join together?
Amino acids join together by peptide bonds (a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O))
OH and H (reaction occurs)
(+H2O) the two hydrogen and oxygen are kicked out as a water molecule
branch forms between the two amino acids
which is called a condensation reaction
what is a dipeptide?
a dipeptide is made up of 2 amino acids linked together by a peptide bond