B1 Flashcards
1
Q
what types of things can an organism be?
A
Eukaryotic
Prokaryotic
2
Q
what is Eukaryotic?
A
animals and plants
made from complex cells
3
Q
what is prokaryotic?
A
bacteria
simpler cells
4
Q
structures in an animal cell?
A
nucleus
cytoplasm
mitochondria
ribosomes
cell membrane
5
Q
structures in a plant cell?
A
nucleus
cytoplasm
mitochondria
ribosomes
cell membrane
-cell wall
-chloroplasts
6
Q
structures in a prokaryotic cell?
A
chromosomal DNA
plasmids
cell membrane
flagella
slime capsule
cell wall
Pilli
ribosomes
6
Q
what is a nucleus and what cells is it found it?
A
contains DNA in form of chromosomes that controls cells activities
ANIMAL AND PLANT
7
Q
what is a cytoplasm and what cells is it found it?
A
gel-like substance where chemical reactions take place
ANIMAL, PLANT AND BACTERIA
8
Q
what is a mitochondria and what cells is it found it?
A
where respiration takes place, contain enzymes needed for the reactions
ANIMALS AND PLANTS
9
Q
what is a ribosome and what cells is it found it?
A
where proteins are made
ANIMALS, PLANT AND BACTERIA
10
Q
what is a cell membrane and what cells is it found it?
A
holds cell together controls what goes in and out by providing a selective barrier
.contain receptor molecules that are used for cell communication
ANIMALS, PLANT AND BACTERIA
11
Q
what is a cell wall and what cells is it found it?
A
rigid, made of cellulose gives support for cell
PLANT AND BACTERIA
12
Q
what is a chloroplast and what cells is it found it?
A
where photosynthesis takes place
contain green substance called chlorophyll
PLANT
13
Q
what is a vacuole and what cells is it found it?
A
store nutrients and water- rely for its survival.
store the waste from the cell and prevents the cell from contamination.
PLANT
14
Q
what is a chromosomal DNA and what cells is it found it?
A
1 long circular chromosome
loose DNA
controls cells activity and replication
floats free in cytoplasm
BACTERIA
15
Q
what is a plasmid and what cells is it found it?
A
small loops of extra DNA
contain gene for drug resistance, passed between bacteria
BACTERIA
16
Q
what is a flagella and what cells is it found it?
A
can rotate or move in a whip-like motion to move the bacterium.
BACTERIA
17
Q
what is a Pilli and what cells is it found it?
A
Thread-like structures on the surface of some bacteria that enable the bacteria to attach to other cells or surfaces
18
Q
what is a slime capsule and what cells is it found it?
A
final outer layer
protect bacteria from drying out and from attack by cells of the immune system
BACTERIA
19
Q
what are cells studied using?
A
microscope
-lenses to magnify image
20
Q
what are the types of microscope?
A
.light microscope
.electron microscope
.transmission electron microscope (TEMs)
21
Q
what is a light microscope?
A
invented in 1590s
can see things like nuclei and chloroplasts
22
Q
what is are the parts of a light microscope?
A
.eyepiece lens
.objective lens
.stage
.stage clips
.fine focus
.coarse focus
.light source
.handle (arm)
23
Q
what is the eyepiece lens?
A
look through to see image
magnifies image 10x
24
what is the objective lens?
magnifies image
x4 x10 x40
25
what is the stage on a LM?
supports slide
26
what are the stage clips on a LM used for?
holding slide in place
27
what is the handle (arm) on a LM for?
carry microscope safely
28
what is the light on LM for?
shine through slide so can see image more easily
29
what is the fine focus on an LM for?
bringing image into focus so its clearer
30
what is the coarse focus for on a LM?
move the stage up and down
31
how to prep a specimen before using microscope?
.get a thin slice of specimen so light can shine through it
.clean slide, use pipette water in middle of slide - secure specimen
.tweezers place specimen on slide
.add stain if needed
.add cover slip
32
after prepping specimen what do you do?
when cover slip is on
.clip slid onto stage
.select lowest objective lens
.use coarse focus to move stage to top
.look down eyepiece use coarse focus to move stage down until is just about in focus
.use fine focus to get a clear image
.if want higher magnification swap objective lens and refocus
33
what is magnification?
how many times bigger the image is compared to its real size
34
equation for total magnification?
eyepiece lens mag * objective lens mag
35
equation for magnification?
image size
---------------
real size
36
what is DNA?
polymer made up of two strands forming a double helix.
DNA contains all of an organisms genetic material - arranged into chromosomes
37
what are DNA bases (nucleotide)?
A,C,G,T
38
what bases pair up in DNA, what's this called?
C,G
A,T
complimentary base-pairing
39
what do nucleotides contain?
sugar, phosphate, base
40
what is a polymer?
large complex molecule
long chains of monomers joined together
41
how are proteins made?
reading the code in DNA
42
what are proteins made up of?
chains of molecules called amino acid
42
what is production of proteins called?
protein synthesis
42
where are proteins synthesised?
in ribosomes
43
how is each amino acid coded?
by a sequence of 3 bases in gene - triplet code
44
what is mRNA?
messenger RNA
substance that carries a complementary copy of a gene from the DNA in the nucleus to the ribosomes in the cytoplasm
45
describe how information gets from DNA in nucleus to ribosomes?
1. DNA contains the gene coding for the protein
2. In nucleus - DNA strands unzip, DNA used as a template to make mRNA
3.base pairing ensures its complementary this is called TRANSCRIPTION
4. mRNA molecule goes out nucleus into cytoplasm and joins ribosome
5. Amino acid that match triplet codes on mRNA are joined
6.makes protein coded for by gene, amino acid bought to ribosomes by tRNA. TRANSLATION
46
what is tRNA?
transfer RNA
transport specific amino acids to the ribosome
47
what is transcription?
first stage of protein synthesis
it occurs in the NUCLEUS.
The main purpose is to make an mRNA copy of a gene
48
What is translation?
second step of protein synthesis
where the instructions in the DNA code are translated into a protein molecule
48
what do enzymes control?
cell reactions
49
what are enzymes?
proteins that act as biological catalysts,
meaning they speed up reactions without being used up
50
what are enzymes used for?
speed up the useful chemical reactions in the body
-reduce need to increase temperatures
50
what is the active site?
in an enzyme
bit that joins to the substrate
51
what are parts of an enzyme?
active site
substrate
enzyme
51
what do enzymes have towards their substrate?
high specificity for their substrate
52
why are enzymes 'fussy'?
.need correct
temperature
pH
concentration
52
what is the 'lock and key' hypothesis?
substrate has to fit perfectly inside the active site otherwise the reaction won't be catalysed
53
how does temperature change the rate of an enzyme-controlled reaction?
.higher temp increases rate at FIRST
.gets TOO hot, bonds holding enzyme together will break
-enzyme will become denatured
-loose shape and substrate won't fit - can't catalyse reaction - reaction stops
.optimum temp for most important human enzymes is 37 degrees
54
how does pH have an affect on enzyme-controlled reactions?
.if pH is too high or too low
-affects bonds holding enzyme together - changes shape of active site - denature enzyme
(can't catalyse reaction - reaction will stop)
.optimum pH is often 7
55
how does substrate concentration have an affect on enzyme-controlled reactions?
.more substrates the faster the reaction, more likely an enzyme will meet up and react with a substrate molecule
.however at some point all active sites will become full with substrates and adding more substrates will have NO EFFECT
55
how does enzyme concentration have an affect on enzyme-controlled reactions?
.more enzyme molecules there are more likely a substrate will meet up with an active site
.increasing conc will increase rate of reaction
.if amount of substrate is limited, there becomes a point where there is more than enough enzymes
so it'll have NO EFFECT
56
how to measure affect of pH in an enzyme-controlled reaction?
add buffer solution with different pH
to a series of different tubes containing enzyme-substrate mixture
57
what is respiration?
processes of transferring energy from breakdown of glucose
58
what is respiration controlled by?
so that means what affects it?
enzymes
so rate of reaction is affected by temperature and pH
-EXOthermic
59
what is aerobic respiration?
IN presence of oxygen
.most efficient way to transfer energy
.produces a lot of ATP
59
what are the types of respiration?
anaerobic and aerobic
60
what is the equation for aerobic respiration?
glucose + oxygen → carbon dioxide + water + ATP
61
what is anaerobic respiration?
.NOT in presence of O2
.less energy is transferred per glucose molecules
.less ATP is produced
62
what is the equation for anaerobic respiration for animals?
glucose → lactic acid + ATP
63
what is the equation for anaerobic respiration for plants and fungi?
glucose → ethanol + carbon dioxide + ATP
64
when exercise what happens to rate of respiration?
what will increase and why?
it will increase
-need more oxygen to cells
-breathing rate increases to get more O2 into blood
-HR increases to get oxygenated blood to working muscles
65
what experiment can you do to investigate how exercise affects BR and HR?
HR
.measure and record you resting HR (count pulses for 1 min)
.do gentle exercise e.g walk
.measure and record HR again - immediately after
.then take regular measurements of HR until it has returned back to its resting rate
.record time it takes to go back (recovery time)
.repeat steps but increase intensity of exercise e.g Jog then run
.produce a a bar chart of results
which SHOW how HR is affected by intensity of exercise
.to reduce random errors do it with multiple people and plot an average
.do same to show recovery time and how that is affected
66
what is oxygen debt?
The amount of oxygen required to remove the lactic acid, and replace the body's reserves of oxygen
66
what is an example of anaerobic respiration?
vigorous exercise
NO time for body to supply exercise to working muscles
67
what happens to glucose in anaerobic respiration?
what do you have after anaerobic respiration?
glucose is only partially broken down
oxygen debt
you'll need extra oxygen to break down all LA
68
similarities between anaerobic and aerobic respiration?
substrate in both is GLUCOSE
Both release ATP
take place inside cells
69
differences between aerobic and anaerobic respiration?
---aerobic O2 is present
anaerobic isn't
---aerobic products are CO2 and H2O
anaerobic animals-LA
plants-ethanol + CO2
---aerobic lots of ATP made
anaerobic less ATP made
70
how to test production of CO2?
.use hydrogen-carbonate solution to show living organisms produce CO2
.solution is red - changes to yellow when CO 2 present
71
how to set up experiment to test production of CO2 by beans?
.soak some dried beans in water for couple of days
-start to germinate
-germinating beans will respire
.boil similar sized set of dried beans
-kills the beans so they can't respire
.
.put some hydrogen-carbonate indicator in 2 test tubes
.place platforms of gauze into each test tube to put beans on
.seal test tubes with rubber bung
.leave it all for an hour
.germinating bean solution should turn yellow
72
how can energy transferred by heat during respiration be measured?
using dried beans
.get wet beans (germinated)
.get boiled beans
.add each set of beans to a vacuum flask - leaving some air so they can respire aerobically
.place thermometer into each flask
.seal top with cotton wool
.record temp of flask every day for a week
.beans are well-insulated in flasks
so when germinating beans respire and transfer energy to surroundings (heat) the flasks TEMP will INCREASE
73
what can biological molecules be broken down to?
fuel respiration
73
in the beans respiration (CO2 and energy transferred) experiment why is the a set of boiled beans?
Control beans
so you know the outcome when respiration doesn't happen - how it should stay the same
73
what are large complex carbs?
polymers
-starch, glycogen
74
what are carbohydrates made up of?
simple sugars
carbon, hydrogen, oxygen
74
what are proteins made up of?
amino acids
75
how are carbs broken down?
digested by enzymes in mouth and small intestine
76
what do amino acids contain?
carbon, nitrogen, hydrogen and oxygen
77
how are proteins broken down?
by enzymes in the stomach and small intestine
78
how are lipids broken down?
by enzymes in the small intestine
78
what are lipids made up of?
fatty acids and glycerol
78
what are lipids?
fats and oils
NOT polymers
79
what do lipids contain?
carbon hydrogen and oxygen
80
what solution do you use to test for sugars and what is the colour change if its present?
Benedict's reagent
blue to Brick red if present
80
how to test for reducing sugars?
add benedict's reagent (blue) to a sample and heat it in a water bath (75degree)
if test positive will form a coloured precipitate - brick red
.higher conc of reducing sugar more the colour will change
80
how to test for non-reducing sugars?
.add dilute hydrochloric acid to a sample of solution
.heat in water bath (75degree)
.add sodium hydrogen-carbonate then carry out benedict's test
.coloured precipitate means sugar is present
81
how to test for lipids?
shake test substance with ethanol for about a minute - until it dissolves
pour solution into water
-if any lipids present will show up as a milky emulsion
-more lipids the milkier it goes
81
what are reducing sugars?
one that reduces another compound and is itself oxidized
Glucose, fructose, lactose and maltose
81
what solution do you use to test for starch and what is the colour change if its present?
iodine
browny-orange to blue-black
81
how to test for starch?
add iodine solution to the sample if starch is present it will go forma browny-orange colour to a blue-black colour
if its not present iodine will stay brown-orange
81
how to test for proteins?
add sodium hydroxide solution to make it alkaline
.add copper (II) sulphate solution (blue)
if protein is present it will turn purple
82
What are non-reducing sugar?
cannot donate electrons, therefore they cannot be oxidised
sucrose
82
what solution do you use to test for lipids and what is the colour change if its present?
emulsion test
ethanol
-milky emulsion if present
82
what solution do you use to test for proteins and what is the colour change if its present?
biuret test
(copper(II) sulphate)
blue to purple
82
how do plant make their own food?
photosynthesis
83
what is the equation for photosynthesis?
carbon dioxide + water → (light/chlorophyll) glucose + oxygen
83
what is photosynthesis?
process by which plants convert light energy into chemical energy in the form of glucose. This chemical energy is then used as a source of fuel
84
where does photosynthesis happen?
in chloroplasts
85
what does chlorophyll do?
green
absorbs the light
86
what is balancing number for photosynthesis equation?
666
87
2 main stages of photosynthesis?
energy transferred by light is used to split water into oxygen gas and hydrogen ions
CO2 gas combines with hydrogen ions to make glucose
87
is photosynthesis ENDO or EXO?
why?
ENDOthermic
energy is transferred from environment
88
what affects the rate of photosynthesis?
light intensity
conc of CO2
temp
89
how to measure rate of photosynthesis? (pondweed)
oxygen production
.set up experiment
-tube, water in capillary tube, syringe on tube
.pondweed left to photosynthesise for time
.O2 released will collect in capillary tube
.end syringe is used to draw gas bubble in tube alongside ruler and length of gas bubble is measured
.this is proportional to volume of O2 produced
.experiment repeated to test range of values for factor being investigated -increase temp - add more light
.nothing else should change though
90
what happens in photosynthesis if there isn't enough light?
slows down rate of photosynthesis
91
how to test light intensity - photosynthesis?
.move lamp closer to plant
92
what is light intensity proportional to?
1
------------
d squared
93
what is a thing it called if it is slowing down a reaction?
the limiting factor
94
how to control conc of CO2?
dissolve different amounts of sodium hydrogen-carbonate in water
