science answers Flashcards
1
Q
where do ribosomes live in the cell and what type of synthesis to they engage in?
A
engage in protein synthesis in the cytosol
2
Q
What is cytosol and what does it do?
A
it is a fluid that bathes the interior of the cell, made up of water, proteins, organelles (float there)
It allows functions of life to take place
3
Q
What is the cytoplasm and where is it?
A
Cytoplasm is a thick solution of water, salts and proteins
Located inside the cell membrane
4
Q
rate vs conc graph for 0 order, 1st, 2nd order, what is the grad like?
A
0 = straight horizontal 1 = straight diagonal 2 = curved upwards
5
Q
conc vs time graph for 0 order, 1st, 2nd order, what is the grad like?
A
0 = straight diagonal 1 = curved 2 = curved
6
Q
log(x)=y
A
10^y=x
7
Q
log(10)=?
A
1
8
Q
log(1)=?
A
0
9
Q
The reaction does NOT occur if E^0 is what?
A
Less than 0
10
Q
what direction is the acceleration of an object moving in a circle at a constant speed?
A
Towards the centre of the circle
11
Q
In a pipe/ tube, if area decreases, how does this effect velocity and pressure?
A
the area decrease means a velocity increase and pressure decrease
12
Q
calculation to find flow in a tube
A
flow= vol/time
flow= Av
flow is constant throughout tube!
13
Q
increased heat of solution changes the solubility of the GAS in solution, how?
A
solubility of gas decreases with temp increase (pop goes flat when left out of fridge)
14
Q
strong acid means a what conj base?
HCl (acid) + NH3 =
How does this link dissociation constants of acids and bases?
A
weak conj base
Cl- (weak base) + NH4+ (conj acid)
high pKa = low pKb
15
Q
strong acid has a …. Ka and …. pKa?
A
strong acid has a high Ka and low pKa (low pH for it to dissociate)
16
Q
enthalpy is - means
A
exothermic, rxn makes heat
17
Q
enthalpy is + means
A
endo, rxn takes in heat
18
Q
for a rxn to go spontaneously forward, change in Gibbs E must be
A
negative
0 means rxn is in eqlb - K=1
19
Q
how to calc the critical angle (remember, second medium has lower refractive index!)
A
sin(critical angle)=n2/n1
20
Q
How is frequency of a wave affected when it travels through a diff medium?
A
it is not! wavelenght = velocity / freq
21
Q
How is the wavelength of a wave affected when it travels through a diff medium?
A
It decreases (so does velocity) white light seperates into colours Intensity is the rate of E propagation, when wave enters denser medium, velocity and energy decrease
22
Q
If a characteristic for a gene is sex linked (linked to x chromosome) what sex will get the characteristic more?
A
men (xy) will get characteristic more than (xx)
23
Q
hypo means what
A
slowed down
24
Q
hyper means what
A
overactive
25
how does a neg feedback mech effect deviation from ideal normal value?
neg feedback = decrease deviation / helps maintain homeostasis / reach n maintain eqlbm
26
endocrine glands (glands which secrete hormones etc directly into blood) are under control by what type of feedback mech?
negative feedback mech
27
How do neg feedback mechs work?
parameter is so wrong that it triggers mech to turn on, once the normal value is reached again it turns off - like air conditioning (needs continuous adjustment)
28
How do pos feedback mechs work?
increase deviation from normal value without continuous adjustment (therefore not used to reach eqlbm or regulate homeostasis functions)
29
1 dm^3 = .... cm^3
1000
30
formaldehyde structure
H-(C=O)-H
31
osmosis
WATER transferred across membrane by conc grad
32
diffusion
movement of substance from high conc to low conc across membrane
33
active transport
moves substance AGAINST conc grad
34
how can you see the effect changing parameters have?
must establish eqlbm first then measure
35
Brownsted Lowry
acid: donates proton
base: accepts proton
36
Lewis
acid: accepts electrons
base: donates electrons
37
Arrhenius
acid: produces H+ ions in solution
base: produces OH- ions in solution
38
size of muscle is proportional to .. ?
strength
39
where does left ventricle pump blood to?
body tissues
40
where does right ventricle pump blood to?
lungs
41
Voltage is equal to what?
V=IR
V=W/I
V=E/IT
42
E^0(X^n+/X) for Xn+ +e = X eqn
+ve = reduction, eqn goes forward
-ve or less +ve = ox, eqn goes backwards
E^0 = Ered - Eox
43
Q = ?
Q=IT
44
What is the condition for total internal reflection?
light travels from med of high n to med of low n and the critical angle has been exceeded
45
law of reflection?
n1sin(angle of incidence)=n2sin(angle of reflection)
46
as aerobic resp is more efficient, if someone is doing anaerobic respiration (resp without oxygen) it means that ..?
now has less energy from metabolism to reproduce, grow etc
47
mitochondria
have their own DNA, they are membrane bound organelles which make most of the energy needed for cell's reactions (the E made is stored in ATP)
48
phenotype
an individual's characteristics due to the interaction of the genotype with environment
49
chromosome
thread like structure of nucleic acids and proteins carrying genetic info as genes in the nuc.
50
how does resp make ATP
resp uses the chem E from nutrients and glucose to make ATP (anaerobic resp =less efficient = less ATP)
ATP is still continuously being broken down to make energy
51
what is an obligate anaerobe?
it is a microorganism which is killed by normal atmospheric concs of oxygen, hence only does
52
what is an obligate aerobe?
microorganism that needs oxygen to grow - use oxygen to turn sugars n fats to energy for resp
53
what is a facultive anaerobe?
organism that can make ATP from aerobic resp or fermentation if there is no oxygen
54
what is metaphase?
metaphase is a stage in chromosomal cell division
55
what are eukaryotes?
organism of cell/cells which contain organelles and a nuc which contains DNA in the form of chromosomes. nuc and organelles are enclose din a plasma membrane. Eukaryotes are a type of obligate aerobes
56
If reaction is spontaneous the E^0 is pos or neg?
pos
57
prokaryotic cells
still enclosed cells by plasma membrane BUT has no nucleus or membrane - bound organelles (bacteria, archaea)
58
eukaryotic cells
also enclosed by plasma membrane but contains a nucleus (where DNA is in the form of chromosomes) and organelles
59
what is inside the plasma membrane?
cytosol
60
what is mitochondrion?
an organelle! found in large numbers in most cells and it is where the respiration and energy production occur
Have outer and inner mitochondrial membrane then the fluid inside is called matrix
61
organelle
it's a tiny cellular structure that performs specific functions within a cell, organelles live in the cytosol and often have their own membrane
62
What is a chiral molecule?
a molecule whose mirror image can not be super imposed on to the original molecule
(eg any C with 4 diff groups)
63
enantiomers?
molecules which are mirror images of each other
64
how many enantiomers would a chiral molecule have if there are multiple chiral centres?
number of enantiomers are 2^n where n is the number of chiral centres
65
pKa is what?
log of Ka, the pH where 50% of molecule is acid and 50% base
66
how does metabolic rate change with animal size?
smaller animals have faster heart beat so more oxygen is needed, hence increasing metabolic rate
67
how does muscle effect oxygen uptake?
more muscle (active tissue) needs more oxygen
68
autosomal meaning?
NOT linked to sex chromosome (X) therefore characteristic of that chromosome could go from dad to son and mam to daughter
69
sex linked meaning?
linked to X chromosome (dad-daughter and mam to son)
70
how does temp change solubility of gas in solution?
increasing T = increases S so the gas wants to get out of liq to move more, hence solubility decreases
71
What are the systole and diastole?
```
systole = heart muscle contraction
diastole = relaxation period when heart refills with blood
```
72
How does the heart work?
SAN sends a wave of depolarisation BUT due to the non-conductive tissue between atria and ventricles, the wave of depolarisation has to go down to the apex then it affects the ventricle hence the atria contract before the venticles do. ----- ECG/EKG - electrical conductivity on y axis will show a small lump where SAN wave happens and immediate atrial contraction (systole), line is then flat before v.big spike in electrical activity due to contraction of the ventricle (systole) (this spike hides the repolarisation of the atrium (diastole)) then flat line is followed by repolarisation of ventricle (diastole)
ECG allows us to diagnose problems bc t, time between two peaks (heart rate) should be constant
73
Blood from RHS of heart goes where?
The aorta carries the oxygenated blood from RHS heart to the body, it is deoxygenated and sent back to the heart (LHS)
74
Blood from LHS of heart goes where?
the deoxygenated blood leaves LHS of heart to go to the lungs where it becomes oxygenated and returns to heart
75
exponential doesnt have to mean what?
relating to e, just means graph is increasing more and more rapidly eg x^2
76
convex shapes do what to light?
makes light converge to each other
77
What is optical density and its relationships?
opt density refers to the tendency of that material's atoms to turn the light energy of the wave into into vibrational electron energy before the new wave is re-emitted - increase opt density means slower velocity, frequency is constant
78
what happens to ray when incident angle exceeds critical angle? when light goes from more dense to less dense med
total internal reflection - n1sintheta1=n2sintheta2 can no longer be used!
79
what is an antacid?
something the corrects/prevents acidity
80
circumference?
2 pi r
81
wires in same direction affect magnetic flux how?
take away from each other
82
how does P in air change with whether?
rainy day decrease P, nice day increase P
83
terminal velocity is what
when a free falling object's drag = force from weight, no acceleration
84
how many E/Z isomers are possible for a molecule with n number of freely rotating double bonds?
2^n isomers are poss
85
what is unbroken lineal descent?
characteristic is seen in every gen but doesnt need to be every offspring
86
wave passes through slit to screen creating a wave pattern, how to increase width of waves seen?
increase dist from slit to screen, increase wavelength and decrease width of slit
87
how does K change with increasing T?
if T increase and reaction is endo (takes in heat energy, pos delta H) then K will increase
for exo rxn and increase T means K will decrease
88
which side of the heart is oxygenated blood and where does the oxy blood go?
the left ventricle side (RHS in pic) goes from aorta to body
89
biconvex lens: sign of R1, R2 and F? is R1 on the left or right?
```
R1 = +ve on rhs
R2 = -ve
F = +ve
```
90
Intensity eqn
Intensity = power / area
91
power and energy eqn
E = P x t
92
60 x 60 x25x350 = ?
315 x10^5
93
what does the specific promotor do?
limit how much the cell types can be activated
94
smaller mammals have a .... metabolic rate compared to larger animals?
smaller animals have a more rapid metabolic rate
95
sigmoid shape, as x decreases does it become harder or easier for y to decrease
easier for y to decrease
96
voltage and capacitance eqn
voltage = charge / capacitance
97
if something has -ve feedback, is it possible that it is a precursor for something else?
no
98
negative feedback takes the longest time to start occuring
ye
99
is positive feedback likely to occur in the absence of negative feedback?
no
