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Biology B2 Flashcards

1
Q

what is diffusion

A

the net movement of particles from an area of high concentration to an area of low concentration.

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2
Q

what cannot be diffused

A

solids

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3
Q

why does diffusion happen

A

due to the random movement of particles

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4
Q

whats a concentration gradient

A

a difference in concentration between two areas

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5
Q

the higher the concentration…

A

the faster the particles will move

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6
Q

how do you optimise diffusion

A

maintenance of concentration gradient
large surface area
short diffusion pathway

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7
Q

what do dissolved substances have to pass through to get in or out of a cell

A

cell membrane

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8
Q

what is diffusion mainly used for

A 
getting oxygen around the body
removing co2 from the body 
plants use it for photosynthesis 
USED IN:
the lungs
the placenta
and the small intestine
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9
Q

how are alveoli adapted to their function of diffusion

A

alveoli are wide so have a large surface area
membrane is thin so short diffusion pathway
constant supply of blood (to maintain the high concentration gradient)

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10
Q

what is diffused in the small intestine

A

food nutrients (eg amino acids from fats)

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11
Q

explain how the small intestine is adapted to encourage diffusion

A

the villi are very thin, so thin membrane (short diffusion pathway)
large surface area
constant supply of fresh blood

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12
Q

how is a synapse adapted to use diffusion

A

recycle neuro transmitters
short diffusion pathway
because it curves more neauro transmitters get to receptors
large surface area

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13
Q

examples of diffused substances in the placenta

A

oxygen is diffused between the mother and the baby

nutrients carried to the baby

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14
Q

explain how the placenta is adapted to allow diffusion to the foetus

A

thin cell membrane
a lot of blood supply in the capillaries, for the nutrients to be absorbed by so it can supply it to the growing fetus
large surface area of the blood vessels
nutrients absorbed by fetus

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15
Q

what happens when a cell becomes specialised

A

its structure adapts to suit a particular job it does . eg sperm cells, egg cells, nerve cells

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16
Q

what is tissue

A

a group of cells with similar structure and function working together

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17
Q

multicellular organism …

A

made up of many different cells. some of these cells have differentiated and become specialised to carry out a particular function in the body. a group of these cells working together forms a tissue

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18
Q

DIGESTIVE SYSTEM- what is the order

A 
the mouth
the stomach 
liver and gall bladder
the pancreas
the small intestine
the large intestine
ANAGRAM: mother sometimes loves pumpkin spice lattes. #totallyjustmadethatup
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19
Q

what does the mouth the do in the DS

A

food is broken down by the teeth (mechanical breakdown)

then mixed with saliva and swallowed

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20
Q

what does the stomach do in the DS

A

a muscular bag filled with hydrochloric acid can expand

2 things happen- food is broken down by acid and the microbes are destroyed

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21
Q

what does the liver and gall bladder do in the DS

A

liver produces bile which helps digest fats, filters blood

gall bladder stores bile

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22
Q

what does the pancreas do in the DS

A 
produces enzymes responsible for breaking down macromolecules
produces hormones (insulin)
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23
Q

what does the small intestine do in the DS

A

food enters from the stomach, it passes along the small intestine where the soluble food is taken into the blood through the walls

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24
Q

what does the large intestine do in the DS

A

waste material is passed through into the anus

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25
what is the equation for respiration
glucose + oxygen → carbon dioxide + water (+ energy)
26
what are mitochondria
they are tiny rod shaped parts that are found in almost all plant and animal cells. they have a folded inner membrane - provides a large surface area for the enzymes involved in aerobic respiration the enzymes CONTROL reactions
27
why does respiration happen
it happens so that energy can be released from glucose and used for a variety of reasons
28
what is respiration
a chemical reaction in the body
29
where does respiration occur
in the mitochondria
30
differences between anaerobic and aerobic respiration
aerobic- uses oxygen and glucose and the product is co2 and h2o anaerobic- uses glucose and produces lactic acid (which is broken down by o2)
31
what is oxygen debt
oxygen needed to break down lactic acid after exercise until your breathing returns to normal
32
what is the link between respiration and muscle contraction
in order for our muscles to contract respiration must happen as it relies on energy released during respiration
33
how are muscle adapted to release energy
having lots of mitochondria
34
what are enzymes
are proteins that catalyze (speed up) chemical reactions
35
short chains of protein molecules are called...
POLYPEPTIDES
36
LOCK AND KEY MODEL explain...
substrate SPECIFIC to an enzyme attatches to the active site on the enzyme. this turns into an enzyme substrate. the bonds in the substrate become weakened. the substrate breaks off and breaks in half creating two products. after the products break off they are used up (but no one knows what happens)
37
when it gets too hot what happens to your enzymes
they become denatured
38
what does it mean when an enzyme becomes denatured
its shape changes drastically
39
why does ph denature enzymes
Anything that changes the shape of the active site stops the enzyme from working. The shape of the active site is affected by pH. This is why enzymes will only work at a specific pH.
40
what are examples of enzymes in the industry
baby food biological detergent sugar syrup fructose (a lot sweeter than glucose)
41
why is the cost of enzymes high
expensive to produce (need to culture them in a lab, keep them seperate) need to keep at one temperature/pH so they dont denature (control the environment)
42
why is the cost of enzymes low
less heat energy needed for them to be produced lower pressure needed quicker reactor (theyre catalysts)
43
how many pairs of chromosomes do we have
23!
44
what is a somatic cell
has two versions of each chromosome- one from each parent. we call this type of cell DIPLOID
45
describe the process of mitosis
mitosis begins with one parent cell DNA in the parent cell is copied (to prepare the cell for division) the chromosomes line up along the centre, its the easiest way to make sure its split 50/50 the two copies of each chromosome are pulled apart by spindle fibres the parent cell begins to divide two identical daughter cells are formed
46
stem cells are what type of cell
undifferenciated
47
when are they found
in early embroyonic development
48
what did mendel study
pea plants
49
why didnt people accept mendels ideas?
he couldnt explain recessive and dominant genes and say why it happened
50
what did mendels experiment with peas show
there were distinct units of inheritance which were not blended together. because when bred a pink and white pea plant all the offspring were pink as pink was the dominant allele.
51
what is an allele
different forms of the same gene
52
what is homozygous
2 copies of the same allele
53
what is heterzygous
2 alleles which are different
54
what is differentiated
specialised for a specific function
55
recessive definition
the characteristic that will show up in the offspring only if both the alleles are inherited
56
what is meiosis
type of cell division that produces four gametes
57
cystic fibrosis (CF) what does it effect
respiratory and digestive system stops you from being able to clear your lungs, mucus builds up in lungs, cilia stop working and die dont produce enough bile in the digestive system, especially affects pancreas
58
is CF curable
no, it is life limiting and incurable
59
what type of disease is CF
inherited. BUT the allele for CF is RECESSIVE
60
when you have a genetic disease which letter is bad
the small one
61
if you are a carrier what are you
a heterozygous eg Cc
62
huntigtons disease features
degenerative disease fatal and no cure very rare but serious
63
what happens in huntingtons disease
nerve cells in the brain degenerate, start to lose control over your body
64
what is the allele of huntingtons disease
DOMINANT you CANNOT be a carrier
65
explain dominant diseases in punnet sqaures
one capital letter, if its dominant, means you've got it. if you have any capital letters with a dominant disease it means you've got it
66
sickle cell anaemia factors
is a blood disorder, which affects your circulation can lead to blood clotting oddly shaped red blood cells red blood cells die quickly and also block vessels can lead to a range of complications and be painful
67
can you be a carrier of SCA
yes, means its recessive
68
explain recessive diseases in punnet squares
if you have a recessive disease 2 small letters means youve got it. 2 big letters means you havent. 1 big and 1 small letter means youre a carrier
69
what is meant by recessive
only expressed if dominant allele is not present
70
give 1 ethical objection to ethical screening
you are destroying embroyos
71
give one reason in favor of embroyo screening
you can see what embroyos have a genetic disease and prevent it
72
where does meiosis occur
in the cell nuclei
73
how many divisions does meiosis do
produces 4 nuclei with half the original no. of chromosomes in each
74
what type of cell does meiosis create
HAPLOID cells (all cells are different from each other and parent cell)
75
how many chromosomes are in the daughter cells of meiosis
only 23 ALL TOGETHER (only half a SET)
76
how many cells does meiosis produce
four (each cell has half the chromosomes needed)
77
what is the function of meiosis
it helps to reproduce (produces gametes- egg and sperm cells)
78
what do plant cells have that animal cells do not
a cell wall
79
what are the three groups of enzymes in digestion and what is their substrate
enzyme: amylase substrate: carbs enzyme: protease substrate: proteins enzyme: lipase substrate: fats
80
3 industrial uses for enzymes
baby food biological detergent lipase used in pharmaceutical industry
81
formula for aerobic respiration
oxygen + glucose ----> carbon dioxide and water
82
explain how the change in DNA can result in the production of an enzyme that does not work
DNA codes for amino acids, which make up proteins. these proteins make up enzymes. the change of the amino acid sequence will change the shape of the enzyme active site. this means the enzyme won't work as the substrate can't fi

Biology B2 (1 decks)

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