Unit 2 Biology Flashcards
1
Q
What are the 7 nutrients? (7)
A
1- Protein
2- Carbohydrate
3- Lipids (fat)
4- Fibre
5- Vitamins
6- Minerals
7- Water
2
Q
What is the use of protein in the body? (1)
A
- They are used for growth and repair of tissues
3
Q
What is the use of carbohydrates in the body? (2)
A
- Provide glucose to be used in respiration
- To release energy which is provided to the body
4
Q
What is the use of lipids in the body? (2)
A
- Provide insulation
- And serve as long-term energy reserves for the body.
5
Q
What is the use of fibers in the body? (1)
A
Supports movement of food through the bowels
6
Q
What is the use of water in the body? (1)
A
Hydrates cells and help regulate body temperatures
7
Q
What is the use of Calcium (mineral) In the body? (1)
A
Making teeth and bones
8
Q
What is the use of Iron (mineral) in the body? (1)
A
Helps make haemoglobin to carry oxygen around the body
9
Q
What is the use of vitamin A in the body? (1)
A
It creates a chemical in the eye for good eye vision
10
Q
What is the use of vitamin C in the body? (2)
A
- It forms a protein called collagen
- And the collagen helps grow and repair tissues in the body
11
Q
What is the use of vitamin D in the body? (1)
A
Helps the bones absorb calcium
12
Q
What are some sources of protein? (3)
A
- Egg
- Chicken
- Beef
13
Q
What are some sources of carbohydrates? (3)
A
- Rice
- Bread
- Potato
14
Q
What are some sources of lipids? (3)
A
- Avocado
- Oil
- Nuts
15
Q
What are some sources of fibres? (3)
A
- Fruits
- Vegetables
- Nuts
16
Q
What are some sources of water? (2)
A
- Water
- Fruits
17
Q
What are some sources of Calcium (mineral)? (3)
A
- Milk
- Vegetable
- Dairy products
18
Q
What are some sources of Iron (mineral)? (3)
A
- Beans
- Red meat
- Nuts
19
Q
What are some sources of vitamin A? (3)
A
- Carrot
- Butter
- Liver
20
Q
What are some sources of vitamin C? (3)
A
- Fruits
- Vegetables
- Potato
21
Q
What are some sources of vitamin D? (3)
A
- The sun (is not a source, but helps the body PRODUCE vitamin D)
- Liver
- Egg YOLK
22
Q
What elements make up carbohydrates? (3)
A
- Carbon
- Hydrogen
- Oxygen
23
Q
What elements make up lipids? (3)
A
- Carbon
- Hydrogen
- Oxygen
24
Q
What elements make up proteins? (4)
A
- Carbon
- Hydrogen
- Oxygen
- NITROGEN
25
What is a monomer and give an example of one (2)
- A small molecule that can COMBINE with others to form a polymer
- Example: Amino acids
26
What is a polymer and give an example of one (2)
- It is a large molecule made by REPEATING UNITS of small molecules called monomers
- Examples: Proteins and carbohydrates
27
What are the 3 types of carbohydrates? (3)
- Starch
- Glycogen
- Cellulose
28
What is the monomer of carbohydrates (including the 3 types)? (1)
Glucose
29
What forms are starch found as? (2)
- Amylose
- Amylopectin
30
What makes up lipids? (what are the monomers of lipids?) (2)
- 3 Fatty acids
- 1 Glycerol
NOTE: THESE ARE THE MONOMERS OF LIPIDS. HOWEVER, LIPIDS ARE NOT CONSIDERED AS POLYMERS THEMSELVES
31
What is the monomer of protein (a polymer)? (1)
Amino acids
32
How would you test a sample of food to know if carbohydrate (starch) is present? (5)
- First, you would crush the food sample using a pastel and mortar and put it into a dry and clean test tube
- and add some distilled water into the test tube and gently shake it
- Then put 5 drops of IODINE into the test tube
- Observe the colour change and positive result is that the solution will have a blue-black colour
- Negative result is if the solution remains having a orange-brown colour (colour of reagent)
33
How would you test a sample of food to know if protein is present? (5)
- First, you would crush the food sample using a pastel and mortar and put it into a dry and clean test tube
- and add some distilled water into the test tube and gently shake it
- Then put 5 drops of BIURET REAGENT into the test tube
- Observe the colour change and positive result is that the solution will have a purple colour
- Negative result is if the solution remains having a blue colour (colour of reagent)
34
How would you test a sample of food to know if reducing sugars (glucose) is present? (6)
- First, you would crush the food sample using a pastel and mortar and put it into a dry and clean test tube
- and add some distilled water into the test tube and gently shake it
- Then put 5 drops of BENEDICTS SOLUTION into the test tube
- Then prepare a hot waterbath and place the test tube in the waterbath for 5 minutes
- Observe the colour change and positive result is that the solution will have either a Green colour (low concentration), Yellow colour (medium concentration), or have a Red colour (high concentration)
- Negative result is if the solution remains having a blue colour (colour of reagent)
- NOTE: This is the main test you need to know and reducing sugars is just another name for glucose
35
How would you test a sample of food to know if lipids are present? (6)
- First, you would crush the food sample using a pastel and mortar and put it into a dry and clean test tube
- Add ETHANOL into the test tube and gently shake it
- Prepare a separate test tube containing distilled water
-And place the solution from the other test tube into the test tube containing distilled water
- Observe the test tube and look for a cloudy white emulsion to form over the solution and if there is, then lipids are present
- Negative result is if the solution remains clear
- NOTE: This is called the emulsion test
36
Give 2 safety precautions when preforming ALL food tests and explain them (2)
- Wear safety goggles as the reagent used in the test could be an irritant to the eyes
- Carefully place the test tube into the waterbath to prevent hot water from splashing on you
37
What is a good temperature for the water to be in the waterbath? (1)
80 degrees celsius
38
What are enzymes? (1)
They are biological catalysts that speed up chemical reactions in living organisms WITHOUT being USED UP in the process
39
What is a catalyst? (1)
Something that increases the rate of a reaction but remains UNCHANGED at the end of the reaction
40
What is activation energy? (1)
Minimum energy required for a chemical reaction to occur
41
What is the active site on an enzyme? (1)
It is an area on the enzyme where a SPECIFIC substrate will bind
42
What is a substrate? (1)
A molecule that an enzyme works on
43
What type of molecule are enzymes made up of? (1)
Enzymes are made up of proteins
44
Describe and explain the process of a substrate binding and making products with an enzyme (6)
- The enzymes active site is complementary to the substrate
- meaning that specific enzymes will ONLY BIND with a specific substrate
- The substrate binds to the enzymes complementary active site ACCORDING to the LOCK AND KEY theory
- Once it is bound to the active site, it is now called an enzyme-substrate complex
- The enzyme catalyses and converts the substrate into products
- After the reaction, the enzyme catalyses with another substrate
45
How do enzymes speed up chemical reactions? (2)
- Enzymes lower the activation energy required for chemical reactions.
- This makes it easier for substrates to convert into products, speeding up the reaction
46
How does temperature affect enzyme activity (also talk about when it exceeds optimum temp)? (4)
- A high temperature gives the enzymes more kinetic energy
- This allows the enzyme to have MORE SUCCESSFUL COLLISIONS with substrates
- Due to more successful collisions, reactions with the enzyme and substrate will happen more frequently therefore an increase in the rate of reaction
- However, there is a limitation because if the temperature exceeds the optimum temperature, then the enzyme will start to denature and the rate of reaction starts to decrease
47
What does denature mean in terms of enzymes? (1)
It is when the shape of the active site on an enzyme changes therefore no substrate will be able to bind with it
48
How does the PH affect enzyme activity? (2)
- Enzymes work best at their optimum PH, which is specific to each enzyme
- A PH too high or too low can change the enzymes active site shape, causing it to denature.
49
What is meant by the term deficiency? (1)
Having a lack of essential nutrients needed for health
50
What deficiency is caused by having a lack of carbohydrates in the body? (1)
Starvation
51
What does starvation do to the body? (2)
- It causes the body to break down fat and muscle for energy
- leading to muscle loss which weakens the body
52
What deficiency is caused by having a lack of vitamin A in the body? (1)
Having blurry vision
53
What does blurry eyes do to the body? (1)
It prevents clear vision
54
What deficiency is caused by having a lack of vitamin C in the body? (1)
Scurvy
55
What does Scurvy do to the body? (1)
It causes gums in the mouth to start bleeding
56
What deficiency is caused by having a lack of vitamin D in the body? (1)
Rickets
57
What does Rickets do to the body? (2)
- Rickets make the bones softer
- This causes bones to be more weaker therefore making the bone change shape
58
What deficiency is caused by having a lack of Iron in the body? (1)
Anaemia
59
What does Anaemia do to the body? (3)
- It causes the body to NOT PRODUCE ENOUGH haemoglobin
- This causes a lack of oxygen that is carried by RBC
- so cells in the body then lack oxygen
60
What deficiency is caused by having a lack of protein in the body? (1)
Pop belly (bloating)
61
What does pop belly do to the body? (2)
- Causes the body to have a higher risk of getting diseases
- Such as: heart disease and high blood pressure
62
How is obesity caused? (1)
By overeating calories
63
What is the formula for calculating the total amount of energy in food? And also state the units (6)
- Energy in food = (Final temp - Start temp) x mass of liquid x Specific heat capacity of liquid OVER Mass of food
- Temperature = degrees celsius
- Mass of liquid (usually water) = g
- Specific heat capacity = J/g degrees celsius (FOR WATER ITS 4.2)
- Mass of food = g
- Energy in food = J/g
64
Describe the practical for finding out the amount of energy in food (8)
- Weigh the food sample to measure its mass.
- Weight the EMPTY test tube and record the mass. Then weight the test tube with the desired amount of water and record. Subtract final mass-Initial mass to get the mass of liquid in grams.
- Then record the initial temperature of the water.
- Ignite the food sample using a Bunsen burner or spirit burner.
- Hold the burning food under the test tube of water to transfer the heat.
- Allow the food to burn completely while the heat raises the temperature of the water.
- Measure the final temperature of the water.
- Now you will have all the necessary values and plug the values into the formula for finding the amount of energy in food
65
Why would a calorimeter provide more valid results when preforming the "amount of energy in food" practical? (3)
- Has a stirrer: Allows water to be heated more equally
- Has insulation: Prevents heat loss from the surroundings
- Has ignition wires: Heats food sample equally
66
What are some factors that can affect dietary needs of different people? (4)
- Age
- Gender
- Activity level
- Whether or not the person is pregnant
67
What are the dietary requirements for young and old people? (2)
Young people - High energy, Lots of protein, vitamins and iron
Old people - Low energy, some protein and mainly vitamins
68
What are the dietary requirements for males and females? (2)
Males - More calories and protein due to larger muscle mass
Females - Less calories and more iron due to blood loss during menstruation
69
What are the dietary requirements for different activity levels? (3)
- The more active a person, the more energy they will require
- Therefore an active person will need large proportions of protein for growth and carbs for energy
- Whereas a less active person will need less energy
70
What are the dietary requirements for a pregnant woman? (3)
- Need an increased calorie intake for themselves and the foetus
- Needs more calcium for foetus bone development
- Needs more protein for foetus growth
71
What are the 6 main enzymes? (6)
- Amylase
- Maltase
- Pepsin
- Trypsin
- Peptidases
- Lipase
72
What molecule does Amylase break down? (1)
Amylase (enzyme) breaks down starch (substrate) into maltose (product)
73
What molecule does Maltase break down? (1)
Maltase (enzyme) breaks down maltose (substrate) into glucose (product)
74
What molecule does Pepsin break down? (1)
Pepsin (enzyme) breaks down proteins (substrate) into peptides (product)
75
What molecule does Trypsin break down? (1)
Trypsin (enzyme) breaks down proteins (substrate) into peptides (product)
76
What molecule does Peptidases break down? (1)
Peptidases (enzyme) breaks down peptides (substrate) into amino acids (product)
77
What molecule does Lipase break down? (1)
Lipase (enzyme) breaks down lipids (substrate) into fatty acids and glycerol (product)
78
Where is Amylase made in the body? (2)
Salivary glands and pancreas
79
Where is Maltase made in the body? (1)
WALL of Small intestine
80
Where is Pepsin made in the body? (1)
WALLS of stomach
81
Where is Trypsin made in the body? (1)
Pancreas
82
Where is Peptidases made in the body? (1)
WALLS of small intestine
83
Where is Lipase made in the body? (1)
Pancreas
84
Where does Amylase act in the body? (2)
Mouth and small intestine
85
Where does Maltase act in the body? (1)
Small intestine
86
Where does Pepsin act in the body? (1)
Stomach
87
Where does Trypsin act in the body? (1)
Small intestine
88
Where does Peptidases act in the body? (1)
Small intestine
89
Where does Lipase act in the body? (1)
Small intestine
90
What is the optimum PH of Amylase? (1)
7-8
91
What is the optimum PH of Maltase? (1)
7-8
92
What is the optimum PH of Pepsin? (1)
2-3
93
What is the optimum PH of Trypsin? (1)
7-8
94
What is the optimum PH of Peptidases? (1)
7-8
95
What is the optimum PH of Lipase? (1)
7-8
96
What PH range is acidic? (1)
0-6 (Less than 7)
97
What PH is neutral? (1)
7
98
What PH is alkaline? (1)
8-14 (Above 7 up to 14)
99
What is the role of catalase (enzyme)? (1)
Breaks down the toxic waste product Hydrogen peroxide into oxygen and water
100
Where is catalase (enzyme) mainly found in?
The liver
101
Describe the practical for finding how heat (temperature) affects the productivity of catalase (enzyme) (6)
1) Take one piece of fresh liver and one piece of boiled liver.
2) Cut them to make sure they are the same mass
3) Place each piece in a separate test tube.
4) Add the 5ml of hydrogen peroxide to each test tube and start the stopwatch.
5) After 5 minutes record the height of the froth produced.
6) Repeat the experiment.
NOTE: Results are: The boiled liver will form less broth as catalase has been denatured therefore the enzymes dont act as well. Whereas the fresh liver will form more broth because catalase is still active
102
What is the definition of ingestion? (1)
The process of taking in food
103
What is the definition of mechanical digestion? (1)
The PHYSICAL act of breaking down food (without using chemicals)
104
What is the definition of chemical digestion? (1)
Process of breaking down large, INSOLUBLE molecules into smaller, SOLUBLE molecules using chemicals
105
What is the definition of absorption? (1)
The movement of digested food molecules through the WALLS of the small intestine into the blood
106
What is the definition of assimilation? (1)
The movement of digested food molecules INTO THE CELLS of the body where they are used
107
What is the definition of egestion? (1)
The removal of undigested food
108
What is the definition of excretion? (1)
The removal of METABOLIC waste from the body
109
Definition of the digestive system? (1)
A group of organs that work together to break down food, absorb nutrients, and remove waste (This includes organs where food does NOT pass through bur helps in digestion AND also includes organs where food passes through)
110
Definition of the alimentary canal? (1)
The passage where food passes through the body from mouth to anus during digestion (ONLY includes organs where food passes through)
111
What organs are involved in the digestive system? (11)
- Mouth
- Salivary glands
- Oesophagus
- Stomach
- Liver
- Gallbladder
- Pancreas
- Small intestine
- Large intestine
- Rectum
- Anus
112
What organs are involved in the alimentary canal? (7)
- Mouth
- Oesophagus
- Stomach
- Small intestine
- Large intestine
- Rectum
- Anus
113
Describe how the digestive system works (the full journey of food through the body) (9)
- Food is broken down using the mouth and mechanical digestion occurs
- Salivary glands breaks down food CHEMICALLY at the same time and turns food into bolus
- The bolus then goes into the oesophagus and nerves trigger peristalsis in the oesophagus which is a muscle contraction to push bolus down into the stomach
- The stomach then also triggers peristalsis as the walls of the stomach pound the bolus and breaks down into chunks
- Enzymes and HCL in the stomach wall starts to dissolve the chunks and and turns it into chyme
- The chyme is then sent down into the duodenum (first part of small intestine) where bile is secreted from the gallbladder and the pancreas secretes enzymes onto the chyme
- The broken down chyme then goes to the small intestine where nutrients are absorbed using the vili
- Fibres, water and dead cells are left out and go into the large intestine where water is absorbed
- The end result is called facies which is stored in the rectum ready to be released through the anus
114
What is bile? (1)
Digestive juice which is released into the duodenum
115
Where is bile produced? (1)
In the liver
116
Where is bile stored? (1)
In the gallbladder
117
What is the PH nature of bile? (1)
It is an alkaline
118
What are the functions of bile? (4)
- Emulsifies (breaks down) large lipids into smaller droplets
- to increase the surface area, allowing lipase (enzyme) to break it down more easily
- Neutralises the ACIDIC CHYME by increasing its pH to an optimal level
- for enzymes in the duodenum to break down nutrients more easily
119
What types of enzymes does the pancreas release? (3)
- Amylase
- Lipase
- Trypsin
120
What is peristalsis? (1)
A wave-like CONTRACTION of muscles in the digestive tract that moves food along the digestive system
121
What is the duodenum? (1)
The FIRST part of the small intestine where bile and digestive enzymes are secreted
122
What is passed into the duodenum? (1)
Chyme from the stomach
123
What is the vili? (1)
They are tiny, finger-like projections found in the small intestine
124
What is the main function of the villi? (1)
To increase the surface area INSIDE the small intestine to absorb nutrients into the bloodstream
125
What is one adaptation of the small intestine? (1)
It has lots of villi INSIDE in order to increase surface area for absorption
126
Name and explain 4 adaptations of villi (8)
- The vili has MICROVILLI on it
- This further allows the surface area of the small intestine to increase therefore more nutrients can be absorbed at the same time
- The vili also has a thin EPITHELIUM (tissue on the surface of the small intestine) which is one cell think
- This increases diffusion rate of nutrients as the diffusion pathway is shorter therefore makes it easier for nutrients to diffuse through the vili and into the blood capillary
- Has blood capillaries
- Helping maintain a steep concentration gradient by transporting nutrients away from the villi
- Has lacteals
- This allows fats to be absorbed into the lacteals and get transported around the body
127
Explain one adaptation of the epithelium (2)
- The cells of the epithelium are packed with mitochondria
- This allows the mitochondria to produce ATP for active transport (eventually, as the nutrients get absorbed, there will soon be less outside the vili and more inside the vili, therefore active transport is needed to bring the nutrients in)
128
Where do the nutrients go to after being absorbed in the vili? and name the vein it goes through (2)
- The nutrients go to the liver
- Through the HEPATIC PORTAL VEIN
129
Which part of the small intestine are nutrients absorbed in? (1)
- They are absorbed through the WALLS OF THE ILLIUM on the small intestine
