MB S1 Flashcards
1
Q
What are enzymes?
A
Enzymes are proteins, that have amino acids as their building blocks.
2
Q
What are the main elements that make up the amino acids in the proteins?
A
Carbon, Nitrogen, Oxygen and Hydrogen
3
Q
What is the role of enzymes?
A
They control the rate of chemical reactions in the body. They usually speed up reactions.
4
Q
What is a catalyst?
A
A catalyst is a substance that speeds up a chemical reaction.
5
Q
How is a catalyst and enzyme similar?
A
Enzymes are organic catalysts, as they also speed up reactions within the body.
6
Q
What is specific about a catalyst when involved in a reaction?
A
Whilst the catalyst speeds up the reaction, they do not become apart of the reaction. And therefore can be reused over and over again (so can enzymes)
7
Q
How is an enzyme held together?
A
The enzyme is held into a specific shape with weak hydrogen bonds.
8
Q
Are enzymes specific to their uses?
A
Yes, there are specific enzymes for different chemical reactions around the body.
9
Q
What type of Catalyst is a enzyme?
A
An Organic Catalyst
10
Q
What does an enzyme do?
A
Speed up chemical reactions.
11
Q
What model best describes the functions of an enzyme?
A
A lock and Key model
12
Q
How does a enzyme help the speed of a chemical reaction?
A
It lowers the activation energy.
13
Q
What is the active site?
A
The active site is the small part of an enzyme where the substrate molecules bind and undergo a chemical reaction.
14
Q
How does this chemical reaction occur on the active site?
A
The substrate collides with the active site of the enzyme… where the chemical reaction then occurs. Acting as a organic catalyst.
15
Q
Enzymes are made of…
A
…proteins (chains of amino acids) which are held together by weak hydrogen bonds.
16
Q
heat and acids can break the hydrogen bonds… which then change?
A
The shape of the enzyme
17
Q
What can heat and acids do to the weak hydrogen bonds in an enzyme?
A
They break them, which then change the specific shape of the enzyme.
18
Q
When an enzyme is broken with heat or an acid, it changes the nature of the enzyme. What is the term that explains this?
A
The enzyme is “denatured”
19
Q
What is metabolism?
A
The sum total of all the chemical reactions that occur in an organism in order to maintain life.
20
Q
What is the role of an enzyme in terms of acting as an organic catalyst?
A
Enzymes are organic catalysts. A catalyst is a general term for any substance that speeds up or brings about a chemical change, without itself being used up.
21
Q
What do enzymes control?
A
All the chemical processes within living systems. Enzymes are produced within living cells.
22
Q
What is the chemical composition of an enzyme?
A
Enzymes are proteins. They are made up of amino acids that are linked and then folded to produce a 3-D structure. The folded shape is related to enzyme specificity.
23
Q
Each enzyme catalyses a…
A
distinct chemical reaction.
24
Q
There are two models which identify the Specificity of the enzymes, these are known as?
A
The lock and key model and also the induced-fit Model
25
Whats the Lock and Key Model?
A lock and key model for enzyme specificity shows that a certain enzyme can only react with a certain substrate because of the shape of its active site which correlates to the shape of the substrate. Neither chemical will change to fit the other.
26
Whats the Induced-Fit Model?
The shape of the active site and the substrate molecules will both modify slightly, so the enzyme can react with more substrates. These enzymes have a lower specificity.
27
What is pH?
The pH is a way of describing the acidity of a substance. A pH of 7 is neutral, which means it is neither acidic nor alkaline. High acidity is shown by a lower pH.
28
How are enzymes related to pH?
Enzymes have an optimum pH for activity, for example digestive enzymes in the stomach work best under conditions below pH 6. Changing pH reduces an enzyme’s activity.
29
Why is the maintenance of a constant internal environment important for optimal metabolic efficiency?
- Enzymes control all metabolic processes in the body.
- Enzymes work optimally in an environment where their optimum temperature and pH conditions are met. At temperatures and pH values other than the optimum, the enzymes fail to work efficiently and kept as stable as possible.
- If internal temperatures were to rise too much, enzymes would denature (breakdown).
- If internal temperatures drop, enzymes cannot function.
30
What is homeostasis?
Homeostasis is the process by which the internal environment is kept within normal limits, regardless of the external environmental conditions
31
What conditions does homeostasis include?
temperature, pH, gas levels, water and salt concentrations
32
What do the conditions of homeostasis allow?
This allows the enzyme’s optimal conditions to be met and the body to work efficiently and be kept as stable as possible.
33
Homeostasis consists of two stages, what are they?
1. Detecting changes from the stable state
| 2. Counteracting changes from the stable state
34
During the step of "Detecting changes from the stable state" in homeostasis, what does this include?
A receptor detects a change in some variable in the organism’s internal environment, for example, sensory neurons in the skin pick up a decrease or increase in temperature of air surrounding the body.
35
During the step of "Counteracting changes from the stable state" in homeostasis, what does this include?
An appropriate response occurs that counteracts the changes and thus maintains the stable environment, for example, shivering to generate heat in muscles
36
What is the role of the nervous system in detecting and responding to environmental changes?
The nervous system sends messages to the brain & back to the sensory organs.
37
In the nervous system, the brain, nerves and sense organs all play apart in detecting and responding to environmental changes. what is it for the brain, nerves and sensory organs?
Brain = Processing Information
Nerves = Sending Information
Sense Organs = Detecting Information
38
There is a broad range of temperatures that has life found within it, what is the narrow limits of general life?
-70 degrees C > 200 degrees C
39
In the range of temperatures found for life, what is the temperature range for Hyperthermophiles?
-70 degrees C > 0 degrees C
40
In the range of temperatures found for life, what is the temperature range for most organisms and mammals?
0 degrees C > 50 degrees C
41
In the range of temperatures found for life, what is the temperature range for Extremophiles?
100 degrees C > 200 degrees C
42
Whats an ectotherm?
An animal that is dependent on external sources of body heat.
43
Whats an endotherm?
An animal that is dependent on or capable of the internal generation of heat.
44
The Australian Diamond python is an ectotherm, or an endotherm?
Ectotherm
45
What is a physiological adaption?
The way an organisms body functions
46
What is a behavioral adaption?
The way an organism acts
47
What is a structural adaption?
It is the physical characteristics of an organism
48
What is a physiological adaption of a Australian Diamond Python in a cold condition?
Lies on eggs and shivers to create more heat within the body.
49
What is a structural adaption of a Australian Diamond Python in a cold condition?
Dark in color to absorb heat, and can therefore tolerate colder temperatures than most snakes.
50
What is a behavioral adaption of a Australian Diamond Python in a cold condition?
Basks in sun to raise body temperature.
Hibernation in winter.
Migration to warmer areas.
51
What is a behavioral adaption of a Australian Diamond Python in a warm condition?
Nocturnal- Hunting at night.
| Burrowing during the day.
52
Is the Australian Red Kangaroo and Endotherm or an Ectotherm?
Endotherm
53
What is a physiological adaption of the Australian Red Kangaroo in a cold condition?
Increased metabolic rate to create more heat within the body.
54
What is a structural adaption of the Australian Red Kangaroo in a warm condition?
Panting to release heat.
Exposed areas of skin on the forelegs to increase evaporative cooling of blood for the area.
Shunting of blood from tail to exposed areas of skin to increase heat loss.
55
What is a behavioral adaption of the Australian Red Kangaroo in a cold condition?
Basking in the sun.
56
What is a physiological adaption of the Australian Red Kangaroo in a warm condition?
Decrease in metabolic rate.
57
What is a behavioral adaption of the Australian Red Kangaroo in a warm condition?
Nocturnal.
Licking forearms to increase evaporation from the skin.
Sitting in the shade.
58
What are some responses made by plants due to temperature change?
Leaf Fall, Radiation, Heat-shock proteins, Transpiration, Die Back, Orientation of Leaves, Seed Dispersal and Vernalisation
59
In a plants response to temperature change what is Leaf fall?
Plants reduce their surface area exposed to heat by dropping their leaves.
This also reduces the amount of water that is lost through transpiration.
60
In a plants response to temperature change what is Radiation?
Some plants living in very exposed areas, such as sand dunes, reduce the amount of heat absorbed by having shiny leaves that reflect solar radiation.
61
In a plants response to temperature change what Heat Shock proteins?
These are proteins produced by plants that are under stress from very high temperatures. These molecules are thought to stop enzymes denaturing, so normal cell reactions can continue.
62
In a plants response to temperature change what is Transpiration?
The movement of water up the plant from the roots to the leaves via the transpiration system serves to cool the plant during hot conditions.
The evaporation of the water from the stomata of the leaves also serve to cool the plant.
63
In a plants response to temperature change what is Die Back?
In harsh conditions the shoots and leaves of a plant may die, but left in the soil are bulbs, roots or rhizoids that will begin to grow again when favourable conditions return.
64
In a plants response to temperature change what is Orientation of Leaves?
Vertical orientation of some leaves has the advantage of reducing the amount of leaf surface area in contact with sun rays, e.g. Eucalyptus leaves hang vertically.
65
In a plants response to temperature change what is Seed Dispersal?
Some Australian natives require extremely high temperatures, such as those produced by a fire, to germinate their seeds.
Plant seeds from species such as Banksia ericifolia are only able to open their seed coats when they are exposed to fire.
66
In a plants response to temperature change what is Vernalisation?
This is when plants must be exposed to cold conditions to produce flowers and therefore reproduce. Plants in alpine regions use vernalisation to reproduce when conditions are more favourable at the end of winter.
The presence of cold conditions will stimulate flowers to grow, and when spring approaches they are almost mature.
67
Whats another name for an organic catalyst?
Enzyme
68
The special molecules that control the chemistry of each cell are?
Enzymes
69
Metabolism is chemistry that is controlled by?
Enzymes
70
Everything that happens inside a living thing is a matter of cell chemistry. which is?
metabolism
71
Metabolism makes up every " " reaction in the body
chemical
72
every reaction requires a catalyst which?
speeds up the chemical reaction.
73
enzymes are molecules of what?
protein
74
Enzymes are highly....
specific, and have a particular 3D shape
75
the particular three dimensional shape of an enzyme fits a .......... perfectly
substrate
76
Enzymes only work effectively in a?
relatively narrow range of temperature and pH (acidity)
77
Many properties of enzymes are related to?
their precise three dimensional shape
78
the enzymes fit the substrate molecules as closely as?
a key fits a lock. "lock and key model" this is why enzymes are substrate specific
79
changes in what can cause for the shape of the enzyme to change?
temperature and pH
80
If the shape of the enzyme is changed slightly it might not fit the substrate properly anymore so?
the reaction cannot run as quickly and efficently
81
Optimum temperature/ph are?
levels at which enzymes work best at
82
steps from amino acid molecules to the product of the enzyme being released.
1. amino acid molecules
2. polymerization
3. polypeptide chain
4. polypeptide chain twists and folds
5. equals a protein in a precise 3D shap, becomes an enzyme
6. enzymes active site has a shape to fit the substrate exactly
7. substrate molecules chemically are attracted to the enzymes active site
8. substrate molecules are brought together and react with eachother
9. product released from enzyme
10. enzyme is left an can react with another substrate.
83
name the steps from amino acid molecules to enzyme to metabolic control
1. amino acid molecules
2. polymerization
3. polypeptide chain
4. polypeptide chain twists and folds
5. equals a protein in a precise 3D shap, becomes an enzyme
6. enzymes active site has a shape to fit the substrate exactly
7. substrate molecules chemically are attracted to the enzymes active site
8. substrate molecules are brought together and react with eachother
9. product released from enzyme
10. enzyme is left an can react with another substrate.
84
The effect of temperature on an enzyme as the temperature rises?
As temperature rises the rate increases because the molecules move faster and are more likely to collide and react.
85
The effect of temperature on an enzyme as the temperature peaks past a certain point?
Beyond a certain peak in temperature the enzymes 3D shape begins to change, therefore the substrate no longer fits the active site well and the reaction slows. if temp though is lowered again the shape of the enzyme is restored.
86
Effect of temperature on an enzyme if temperature reaches an extreme level?
the distortion of the enzymes shape may result in a total shut down. the enzyme could be permanently distorted and cannot be restored with a lower temperature this is then called denaturing.
87
Optimum Temperature in enzymes? are they all the same?
No, all enzymes have a seperate optimum temperature point/range.
in comparison enzymes within mammals will peak around the animals normal body temperature, and only will work in a narrow range of that. though in comparison to thermophillic bacteria from a hot volcanic spring will show a totally different peak in temperature and its most optimum temperature for metabolism performance would kill other organisms.
88
The effect of pH on an enzyme?
Enzymes have an optimum pH (acidity level) for activity. for example pepsin from the stomach shows an optimum pH of about 2 or 3 allowing it to work best in an acidic environment.
89
At optimum pH the enzymes 3D shape is?
ideal for the substrate so the reaction rate is at a maximum
90
At any pH lower or higher than optimum the enzymes shape begins to change, what does this mean?
the substrate no longer fits, so activity is less.
91
At extremes in pH the enzyme can be?
denatured, and show no activity at all.
92
Effect of Substrate concentration on enzymes?
substrate concentration means the amount of compound present that the enzyme has to catalyse, beyond a certain substrate concentration the rate of reaction is limited by the amount of enzyme.
93
Effect of Substrate concentration on enzymes?
substrate concentration means the amount of compound present that the enzyme has to catalyze, beyond a certain substrate concentration the rate of reaction is limited by the amount of enzyme.
94
How is the reaction of substrate concentration of an enzyme different to the general reaction of
"the rate of reaction increases if the concentration of the reacting chemicals is increased?"
with an enzyme substrate concentration reaction, the reaction increases as the substrate concentration goes up initially. soon though the enzyme molecules become saturated with substrate and cannot work any faster. though if more enzyme is added to the solution the reaction rate will go up again until all the enzyme molecules are saturated.
95
Metabolism is a large matter of chemical reactions, of which each reaction is catalysed by an enzyme, enzymes are very sensitive to temperature and pH, therefore in the organisms body they must be maintained at a stable balance. What is the process that does this?
Homeostasis.
96
Whats a feedback mechanism?
a feedback mechanism is a situation where the result of some action feeds back into the system to control the next change in the system.
97
Define positive feedback mechanism?
in a positive feedback system any change reinforces itself by causing more change in the same direction.
this system never reaches stability imagine a bush fire that just grows and grows
98
Define a negative feedback mechanism?
In negative feedback any change causes the next change to be in the opposite direction.
good example is the thermostat control.
the result of this mechanism is that everything remains relatively stable, oscillating up and down a little but staying close within range.
99
Homeostasis is what kind of feedback?
Always negative.
100
Key parts of a negative feedback system are?
A receptor - to measure the conditions
A control centre - to decide how to respond
A effector - which will carry out the commands of the control centre and make the neccesary adjustments to the system.
101
In animals what is largely responsible for carrying out receptor and control centre functions?
the nervous system
102
What does the hypothalamus do in guidance to maintaining a balance?
the hypothalamus is at the base of the brain and monitors blood temperature and sends out command messages for negative feedback.
103
Main parts of a temperature control system in mammals?
Receptor and control centre = hypothalamus at the base of the brain, cells constantly monitor the temperature of blood flowing by, if the temperature varies by even a fraction nerve messages are sent to the effectors.
The effectors = blood vessles, sweat glands, endicrine glands, muscles and body hairs.
104
What does a blood vessel effector do in terms of cooling the body?
dilation occurs, (widening) of veins, arteries, and capillaries near the skin to allow more blood flow out near the skin surface.
this allows more body heat to escape from the skin, thus cooling the body.
105
What does a blood vessel effector do in terms of heating the body?
Constriction. (narrowing) of blood vessels causes less blood to flow near skin, so less heat flows out to the skin to be lost. to more body heat is retained.
106
What does a Body hair effector do in terms of cooling the body?
If the hair follicle is relaxed the hair lies flat and allows heat loss.
107
What does a Body Hair effector do in terms of heating the body?
the hairs stand up with the little tiny muscle it has at its base. this gives goosebumps. the hairs then trap a thin layer of still air against the skin and helos insulate and prevent heat loss.
108
What does a sweat gland effector do in terms of cooling the body?
the sweat glands secrete perspiration. the water evaporates from the skin taking away body heat, this has a powerful cooling effect.
109
What does a muscle effector do in terms of heating the body?
nerve signals can cause the skeletal muscles to begin shivering, this extra muscle activity generates more heat.
110
How do hormones aid in temperature control?
Hormones (endocrine system) are chemicals that control various body functions.
for example the hormone thyroxin (thyroid gland in neck) controls the rate of metabolism. the hormone under the control of the hypothalamus will either reduce or increase metabolic rates depending on whether heating or cooling is necessary.
111
To cope with seasonal cold weather many plants especially in the northern hemisphere shed their leaves, what id this called?
deciduous.
112
Deciduous trees/plants do what to their metabolism during the winter?
they practically shut it down, like an animal hibernating.
113
Why do deciduous trees/plants shed their leaves?
they shed their vulnerable parts that cannot be saved from freezing, and then grow new ones in the spring.
114
When a plant is coping with heat and there is plenty of water how does it respond?
the plants cool themselves by allowing maximum evaporative cooling. the leaves open their stomates and allow transpiration to occur. transpiration lowers the plants temperature seven degrees lower than the ambient temperature.
115
When a plant is coping with heat and its dry as well how does it respond?
desert plants tend to have very small leaves and a stocky stem. this reduces surface area being hit by radiation. for example cacti they have spines instead of leaves and a well rounded thick stem, while also being lightly coloured to reflect alot of radiant heat away. along with very few stomates.
116
Whats an example of a sclerophyll plant?
Australian gum trees
117
How do gum trees get away with all the heat in Australia?
they have small or long narrow leaves. another trick they have is that they allow their leaves to droop vertically. this allows them to catch the morning light for their photosynthesis, but then avoid the radiation at midday.
they also have few stomates and close them during dry seasons.
118
What are the responses of the desert lizard an ectotherm in relation to change in ambient temperature?
- avoiding high temperatures (burrowing or seeking shelter under rocks or grasses in the hottest parts of the day.
- increasing body temperature by basking in the sun in the morning
- raising body away from the surface to allow convection currents to carry heat away
- changing colour.
119
What are the responses of the red kangaroo an endotherm in relation to change in ambient temperature?
- sheltering during the heat of the day
- redirecting blood flow through a dense network of blood vessles in the forelimbs in times of heat stress and then licking the limbs to increase heat loss by evaporation of water.
- releasing heat by panting and sweating
120
Whats an adaption/response of the Australian Bilby in relation to temperature
```
adaptions.
sleeps in underground burrow until dusk.
ears act as radiators for heat loss.
Response.
Plug their burrow at certain temperatures.
```
121
what are the adaptions/responses of the Australian Bilby in terms to regulating their body temperature.
```
adaptions.
sleeps in underground burrow until dusk.
ears act as radiators for heat loss.
Response.
Plug their burrow at certain temperatures.
```
122
what are the adaptions/responses of the Australian Frill necked lizard in terms to regulating their body temperature.
adaption: largely inactive during dry season
response: brief periods of basking in the morning sunrise, raising temperatures slightly above ambient temperatures
123
Compare an endotherm and an ectotherm in correlation to their responses to changes in ambient temperature.
The Red Kangaroo does this:
- sheltering during the heat of the day
- redirecting blood flow through a dense network of blood vessles in the forelimbs in times of heat stress and then licking the limbs to increase heat loss by evaporation of water.
- releasing heat by panting and sweating
The Desert lizard does this:
- avoiding high temperatures (burrowing or seeking shelter under rocks or grasses in the hottest parts of the day.
- increasing body temperature by basking in the sun in the morning
- raising body away from the surface to allow convection currents to carry heat away
- changing colour.
124
For the body to function properly it needs --------- internal conditions
constant
125
the ----------- system and the ----------- (or hormone system) monitor the body and maintain a constant internal environment.
nervous, endocrine
126
enzymes are large ------- molecules which --------- /------ chemical reactions.
protein, speed up
127
The human body temperature is -------- so this will be optimum temperature for the functioning of the -------- in humans.
37 degrees C, enzymes
128
body fluids, such as blood, are constantly changing their temperature and --------- composition. --------- is the process which helps organs respond to correct or adjust these
chemical, homeostasis
129
Changes in body fluids are detected by cells called receptors, these cells send messages to the--------. Organs in the body respond to the brain and restore the fluids to -----------.
brain, normal
130
Humans have a number of ----- and ------- mechanisms so that the can maintain a ------- temperature
cooling, heating, constant
131
Every chemical reeaction in cells is controlled by?
its own enzymes, the enzyme is said to be specific for that chemical reaction.
132
low pH = ?
high acidity
133
chemicals in the blood are detected by?
chemoreceptors
134
thermoreceptors detect?
temperature.
135
light is stimulus of which receptor?
photoreceptor
136
sound, touch, pressure, gravity is stimulus of which receptor?
mechanoreceptor
137
whats the central nervous system made up of?
brain and spinal cord
138
whats the peripheral nervous system made up of?
sensory nerves, and effector nerves.
139
How does the nervous system play a role in detecting and responding to environmental changes?
When the environmental temperature begins to exceed a comfortable level for the body, temperature sensors in the skin detect the temperature change and a sensory neuron conducts a nervous impulse to the hypothalamus found in the brain. Nerve impulses pass this information from the receptors to effector neurons then onto effectors, such as blood vessels, sweat glands, endocrine glands and muscles.
140
Temperature control in humans is controlled by the?
Hypothalamus in the brain which is at the base. it is the temperature control centre.
141
The hypothalamus when receiving information about temperatures learns from skin about the....
external temperature
142
The hypothalamus when receiving information about temperatures learns from blood about the....
internal temperature
143
Human responses to over heating?
- metabolism is reduced, as a result less heat is produced.
- sweating: evaporation has a cooling effect as it takes heat from the body
blood vessels in the skin dilate, allows blood to bring more heat to the surface to be radiated away from the body.
- hairs remain flat, decreasing insulating layer of air.
144
Human responses to becoming too cold?
- Metabolism is increased, produces more heat
- shivering, muscles contract to produce heat
- blood vessels constrict, this keeps blood and warmth deep in the tissues so that heat cannot be lost through skin
- hairs stand up to trap layer of air which insulates the body keeping it war.
145
chemical reactions in the body need?
enzymes.
146
each chemical reaction requires?
a specific enzyme
147
enzymes work best at?
specific temperatures and acidities.
148
constant temperatures and conditions in the body are maintained by?
homeostasis.
149
homeostasis involves detection and counteraction of changes by the....
nervous and endocrine system
150
continual feedback of information to the brain is necessary to...
maintain constant conditions.
151
Each species has its own
optimum temperature range
152
Feature/ Adaption: HOT
| Fur/Mammals and Feathers/Birds
fluffs up to keep hot air away from skin
153
Feature/ Adaption: COLD
| Fur/Mammals and Feathers/Birds
holds insulating layer of air around body to keep heat in
154
Feature/ Adaption: COLD
| SA:V
Large SA allows absorption of heat.
eg. sun baking lizard with flat body
Small SA = Polar bear which has small SA:V which reduces the radiation of heat.
155
Feature/Adaption HOT
| SA:V
Large in small mammals so they loose heat to surrounding air
156
Feature/Adaption HOT
| SA:V
Large in small mammals so they loose heat to surrounding air
157
Feature/Adaption HOT
| Metabolism and Movement
Slows to reduce heat production
| eg. a Kangaroo sleeps in the hot part of the day and is active at dusk and dawn.
158
Feature/Adaption COLD
| Metabolism and Movement
Increases to produce heat, humans shiver and the diamond python contracts its muscles to produce heat.
159
Whats a feature/adaption starting with 'M' in relation to temperature change?
Migration if cold to warmer climate, if too warm to cool climate eg bogong moths.
160
Feature/Adaption HOT
| Blood flow to skin and extremities.
Blood comes to the surface to radiate heat. eg large ears of African Elephant.
161
Feature/Adaption COLD
| Blood flow to skin and extremities
Blood Vessels constrict to keep blood in inner part of body and away from extremities where heat can be lost.
eg. a penguins feet.
162
Temperatures fluctuate more on land than in?
Oceans.
163
The practical is "How increased temperature changes the activity of an enzyme" name an aim for this practical.
To Determine the effect of temperature on the digestion of protein (cooked egg white) by the digestive enzyme system pepsin.
164
name a method matched with the following aim.
"To Determine the effect of temperature on the digestion of protein (cooked egg white) by the digestive enzyme system pepsin"
1. set up four test tubes with 2ml of pepsin solution and a few droops of hydrochloric acid to achieve a pH of 2 by testing it with universal indicator
2. place the test tubes in four separate water baths of 0 degrees C, 37 degrees C, 50 degrees C ad 100 degrees C. allow the temperatures of the test tubes to also adjust.
3. Add small pieces of egg white to each of the test tubes
4. stir the tubes occasionally and after a few minutes observe in which testube the egg white has become a clear egg white.
165
name a result for the practical with the aim "To Determine the effect of temperature on the digestion of protein (cooked egg white) by the digestive enzyme system pepsin"
After a few minutes the egg white in the 37 degrees C
166
name a result for the practical with the aim "To Determine the effect of temperature on the digestion of protein (cooked egg white) by the digestive enzyme system pepsin"
After a few minutes the egg white in the 37 degrees C test tube, the protein became a clear liquid.
167
Name a conclusion for this set of results. "After a few minutes the egg white in the 37 degrees C test tube, the protein became a clear liquid"
Pepsin breaks down protein better at 37 degrees c
168
Name an aim for this investigation "How a change in pH affects the activity of an enzyme"
To determine the effect of pH on the digestion of sugar by the enzyme sucrase
169
Name a method for the aim "To determine the effect of pH on the digestion of sugar by the enzyme sucrose"
1. Set up four test tubes, use 5ml of each specific buffer and 5ml of 5% sucrose solution for each test tube. Check pH with universal indicator. TT 1 should have a pH of 2, TT 2 a pH of 4, TT 3 a pH of 6, and TT 4 a pH of 9
2. Place test tubes in beakers of water at a temperature of 37 degrees C
3. Maintain the test tubes for ten minutes and then test for glucose.
4. Use benedicts solution to test for glucose, add 5 ml of benedicts solution to the reaction mixture and heat until it just boils
5. Observe with pH condition is best for the activity of the enzyme based on the deepest orange color obtained.
170
Name results for the investigation of pH and enzyme activity?
Test tube 2 gave the strongest colour
171
give a conclusion for the results "Test tube 2 gave the strongest colour"
The optimal pH for sucrose is approx. pH 4
172
The practical is how changes in substrate concentration affect the activity of an enzyme. name an aim
Aim: To determine the effect of concentration of hydrogen peroxide
173
The practical is how changes in substrate concentration affect the activity of an enzyme. name an aim
Aim: To determine the effect of concentration of hydrogen peroxide on the speed of its break down by catalase.
174
The aim is "To determine the effect of concentration of hydrogen peroxide on the speed of its break down by catalase" name a method.
1. use a cork borer to cut four identical pieces of potato
2. Set up four test tubes
3. place all test tubes in water baths of 37 degrees C
4. Add 5ml of 1.5%, 3%, 4.5% and 6% of hydrogen peroxide to each test tube (some may need to be diluted)
5. Add a drop of detergent to each test tube
6. Add potato to each test tube
7. Measure and record the height of the foam produced as oxygen bubbles through the detergent.
175
What are the results to the practical that had the Aim "To determine the effect of concentration of hydrogen peroxide on the speed of its break down by catalase"
The level of foam was the highest with 6% hydrogen peroxide
176
The results for the concentration prac are "The level of foam was the highest with 6% hydrogen peroxide" what is the conclusion?
An increase in substrate concentration produces an increase of activity of the enzyme catalase
