Biochemistry 1 Flashcards
1
Q
What is ‘matter’?
A
Everything around us that has mass and occupies space.
2
Q
What is chemistry?
A
The science and study of matter (gases, liquids and solids)
3
Q
List 3 forms of ‘matter’.
A
Gases
Liquids
Solids
4
Q
What is ‘biochemistry’?
A
The science and study of the chemical and physiochemical processes and substances within LIVING organisms.
5
Q
What is the difference between chemistry and biochemistry?
A
Chemistry is the science concerned with substances and various forms of elementary matter, whilst biochemistry is the science concerned with the same in LIVING organisms.
6
Q
What 3 things are atoms made up of?
A
Electrons, Protons and Neurons
7
Q
What are atoms?
A
Small particles that make up ‘matter’. They’re like lego bricks that make up everything in our universe
8
Q
‘bio’ = ______
A
Life
9
Q
An ‘element’ is a substance made up of just one type of _____.
A
Atom
10
Q
Why can’t elements be split up into simpler substances?
A
Because elements are substances made up of just one type of atom (lots of identical lego bricks together)
11
Q
All the elements we know of are in the ______ ______
A
Periodic Table
12
Q
What is the chemical symbol for carbon?
A
C
13
Q
What is the chemical symbol for hydrogen?
A
H
14
Q
What is the chemical symbol for calcium?
A
Ca
15
Q
What is the chemical symbol for magnesium?
A
Mg
16
Q
Name 4 elements from the periodic table
A
Carbon
Hydrogen
Calcium
Magnesium
17
Q
What is the name given to a group of individual atoms joined together by bonds?
A
A molecule
18
Q
How many different elements are normally present in the human body?
A
26
19
Q
There are 4 major elements which account for 96% of the human body. Name them.
A
Carbon
Hydrogen
Oxygen
Nitrogen
20
Q
What is Fe?
A
Iron
21
Q
Name 3 ‘transition metals’
A
Iron
Zinc
Copper
22
Q
Why do transition metals and some other groups of elements on the periodic table interfere with each others absorption?
A
Because they are a similar size and similar chemical reactivity, so compete for the same transporters.
23
Q
Name 3 halogen elements
A
Fluorine
Chlorine
Iodine
24
Q
What are subatomic particles?
A
The components of an atom.
25
How many subatomic particles are there? List them.
3 - Protons, neutrons, electrons
26
Which subatomic particles together form the nucleus of an atom?
Protons and neutrons
27
Which of the subatomic particles carries a positive charge?
Protons
28
Which of the subatomic particles carries no charge?
Neutrons
29
Which of the subatomic particles carries a negative charge?
Electrons
30
Which of the 3 subatomic particles is the smallest?
Electrons
31
State the individual masses of the 3 subatomic particles.
```
Protons = 1 atomic unit
Neutrons = 1 atomic unit
Electrons = virtually no mass at all / nothing
```
32
An element will have an equal number of protons and electrons. True or false?
True
33
What are electron shells?
Layers of electrons moving in groups around the nucleus of an atom.
34
What happens to an atom if it has an electron that isn't paired? What name is given to that atom in this situation?
It becomes very stable.
| Free radical
35
When does an atom become reactive?
If its outer electron shell isn't full, or if it loses an electron.
36
What are free radicals?
Atoms or molecules that have an unpaired electron.
37
What is the difference between atoms and molecules?
Atoms are single neutral particles.
Molecules are neutral particles made of 2 or more atoms bonded together.
38
Are atoms and molecules positive, negative or neutral?
Neutral.
39
Do protons have a positive or negative charge?
Proton = Positive
40
Do electrons have a positive or negative charge?
Electrons = Negative
41
How many electrons can be found in the first electron shell (nearest the nucleus of the atom)?
2
42
How many electrons can be found in the second electron shell?
Up to 8
43
How many electrons can be found in the third electron shell?
Up to 8
44
What is the periodic table?
A list of all the currently known elements
45
Why is the periodic table arranged in particular columns and rows?
To show which elements share similar reactivity and physical properties.
46
In the periodic table, what does the number assigned to each element tell us?
The atomic number tells us the number of protons in the nucleus
47
Potassium (K) has an atomic number of 19. What does this tell us?
That there are 19 protons in the nucleus of a single atom of potassium.
48
A single atom of potassium (K) has 19 protons in it's nucleus (atomic number 19). How many electrons does it have?
19. The number of protons always matches the number of electrons.
49
What does the second (bigger) number attached to an element on the periodic table tell us?
The mass / atomic weight of one atom of that particular element.
50
Potassium carries the atomic number 19, and has an atomic mass of 39. How many neutrons does it have in its nucleus?
20
| 39 - 19
51
All of the elements in column 1 (Group 1) of the Periodic Table react with ______
Water
52
All of the elements in column 1 (Group 1) of the Periodic Table have how many electrons in their outer shell?
1
This means they're very reactive.
53
What name is given to the elements in column 7 of the Periodic Table?
The halogens
54
List 3 elements in the halogen group?
Fluorine, Chlorine, Iodine. Bromine, Astatine
55
Why is iodine important when it comes to thyroid health?
Because it is required to make the thyroid hormones T3 and T4
56
What's different about Column 7 (the halogens) of the Periodic Table, versus the other columns?
The reactivity tends to be higher at the top of the column, rather than at the bottom.
i.e, fluorine is more vigorous in its reactivity than iodine is.
57
Explain why fluorine and chlorine present a risk to thyroid health.
Fluorine and Chlorine are more reactive than iodine, but the thyroid will uptake all of them.
The more reactive halogens will elbow the iodine out of the way, creating problems with the body absorbing and using the iodine properly.
This can cause hypothyroidism.
58
Which of these assigned to an element is always bigger; the atomic mass or the atomic number?
The atomic mass
59
Atomic number = number of _______
Protons
60
Mass number = number of ______ + number of ____
Protons + neutrons
The total mass of an atom is always in its nucleus
61
Number of neutrons = _______ number minus ______ number
Mass number - atomic number
62
What are isotopes?
Atoms of the same element which have a different number of neutrons in their nucleus.
Essentially, isotopes are different versions of the same atom.
The chemical reactivity stays the same, but the atomic weight varies. i.e, isotopes are lighter and heavier versions of the same atom.
63
For every element on the periodic table, there is often more than one version (various isotopes). Give an example of an element to which this applies and describe its isotopes.
Carbon.
Most of the carbon in the universe is carbon 12 (6 protons and 6 neutrons)
But small amounts of Carbon 14 (8 neutrons) exist.
64
What causes an isotope to become radioactive?
An imbalance of protons and neutrons in its nucleus.
The imbalance causes the atom to become unstable, so it's tries to rebalance itself by releasing particles of energy. This is radiation.
65
Name 1 way in which radioactive isotopes are used in medicine.
PET scans (via injected short-lived radioactive isotopes)
66
What is the difference between short-lived and long-lived radioactive isotopes?
Short-lived isotopes release their excess energy quickly (over hours / days), so don't remain radioactive for long.
Long-lived radioactive isotopes release their energy slowly (over days / weeks / months / years), so remain radioactive for much longer.
67
Name 2 diagnostic tests / medical treatments that use radioactive tracers
1. Radiation
| 2. H-Pylori breath test
68
What are radioactive tracers?
Radioactive isotopes that emit gamma rays from within the body
69
What is gamma radiation?
Very high energy wavelengths that damage rapidly dividing cells.
The wavelengths in this type of radiation are so small that they can actually get into the nucleus of the cell, damaging the DNA and making it unviable.
70
What is the downside to medical treatments that utilise gamma radiation?
Gamma radiation is not just specific to unhealthy / cancer cells. It also damages healthy cells.
71
What is the food source for H-Pylori in the stomach?
Urea
72
Electrons always want to be in ______
Pairs
73
What makes one atom want to bond with another?
The drive to pair electrons and end up with a stable/full outer shell.
74
All of the reactions that happen in chemistry are driven by.....
Atoms trying to get a stable/full outer shell of electrons
| either by donating one, stealing one (or more), or sharing
75
There are 3 ways in which atoms can obtain a stable/full outer shell of electrons. What are they?
1. Donate
2. Steal
3. Share
76
Name the 'simplest atom' and explain why it has that name.
Hydrogen is the 'simplest atom'
| Because it has 1 proton, 1 electron and no neurons
77
Why is hydrogen very reactive?
Because it only has 1 electron.
78
In nature, hydrogen atoms don't exist on their own. Why not?
Because they're so reactive (with only 1 electron) that hydrogen always pairs with itself via sharing of electrons, or bonds to something else.
79
What is an 'inert' element?
An element with a full outer shell of electrons.
80
Why are inert elements rarely involved in chemical reactions?
Because they have a full outer shell of electrons, so are not highly reactive.
81
Name the 2 main types of bonding.
1. Ionic bonding
| 2. Covalent bonding
82
Describe what happens in ionic bonding.
Electrons are transferred from one atom to another
83
What is the difference between ionic and covalent bonding?
In ionic bonding, electrons are transferred from one atom to another, in order to form electron pairs.
In covalent bonding, electrons are shared between atoms, in order to form electron pairs.
84
When does Na- become Na+ ?
When it gives away its spare electron.
The charge changes, as it then has more protons (+ve charged) than electrons (-ve charged).
85
What is 'ionisation'?
The process of giving or gaining electrons
86
What does + or - written next to an ion (i.e, Cl-) indicate?
Their positive or negative charge after bonding.
A +ion has more protons than electrons
A -ion has more electrons than protons
Remember: a raw atom has an equal number of protons and electrons (parents and children!)
87
An ion is also known as a _______ particle.
Charged particle.
88
Sometimes atoms give away more than one electron. How might you see this written?
Calcium
| Ca2+ is a calcium atom that has given away 2 electrons.
89
Name the 4 most electronegative elements.
1. Fluorine
2. Chlorine
3. Oxygen
4. Nitrogen
90
Some elements have lots of protons compared to their number of electron shells (i.e, a strong positive centre). These elements are referred to as _________
Electronegative
91
What is the name given to an element that has a strong positive centre and tends to pull shared electrons towards itself?
Electronegative
92
What is the name given to covalent bonds where the electrons are shared, but unequally?
Polar bonds
93
Why do polar bonds occur?
Become some atoms have more electron 'pulling power' than others. They pull shared electron clouds towards themselves.
94
Why are polar bonds important in Chemistry?
Because they create little magnets in our molecules, which allow molecules to stick to each other.
95
Give an example of one of the most important polar bonds in biochemistry.
Oxygen and hydrogen (water)
96
________ bonding is an example of polar bonding, and gives water its surface tension and ability to dissolve so many things.
Hydrogen bonding
97
________ bonding is an example of polar bonding, and gives water its magnetic surface tension (i.e, sticking a glass to a coaster) and ability to dissolve so many things.
Hydrogen bonding
98
What serves as the medium for most chemical reactions in the body?
Water
99
What is the 'Universal Solvent'?
Water
100
Hydrophilic molecules are molecules that have _____ covalent bonds.
Polar
101
Hydrophobic molecules are molecules that have ____-____ covalent bonds.
Non-polar
102
What type of bonds are magnetic-creating bonds?
Polar bonds
103
What is an ion?
A charged particle. It is an atom that has either gained an electron, or given one away.
104
Explain what is meant by an isotope.
Isotopes are chemical elements that are the same elements but with a different number of neutrons. So they have different atomic masses.
i.e, carbon 14, versus carbon 12
105
Describe the association between iodine and fluorine.
They're both halogens (Group 7 on the periodic table). However fluorine is more reactive/powerful than iodine, so an excess of fluorine in the body can push iodine out of the way and compromise thyroid function.
106
How many electrons are required to fill the second electron shell?
8
107
Describe what happens in ionic bonding.
One element (atom) gives an electron to another element, resulting in 2 positive and negatively charged atoms that are attracted to each other.
108
Give an example of a polar molecule.
Water.
109
Explain what is meant by 'The Universal Solvent'.
Water's unique ability to dissolve anything with polar bonds, or ionic compounds (things with positive and negative ions).
110
Electrolytes can conduct ________
Electricity
111
Solutions of ionic compounds are called ________
Electrolytes
112
Name 4 of the key electrolytes in the body.
1. Sodium
2. Potassium
3. Chloride
4. Calcium
5. Magnesium
6. Phosphate
7. Bicarbonate
113
When / how is an electrolyte formed?
When an ionic compound (i.e, salt) dissolves in water
114
List 3 functions of electrolytes within the body.
1. Conducting electricity (essential for nerve and muscle function)
2. Exerting osmotic pressure (essential for water balance)
3. Some play an important role in acid-base balance.
115
Our bodies essentially run on electrical chemistry. True or false?
True
116
Our acid-base balance within the body is often referred to as our _H
pH
117
What does pH stand for?
Potential of Hydrogen
118
What is an acid?
A substance that releases a high amount of hydrogen (H+) ions when dissolved in water.
119
What is a base?
A substance that binds to hydrogen ions in solution.
120
What is the difference between an acid and a base?
An acid releases a high amount of hydrogen ions when dissolved in water, whilst a base binds to hydrogen ions in a solution.
121
What is the pH of water?
7
122
More more hydrogen a substance releases in water, the ____ its pH, and the more acidic it is.
Lower
123
What is OH-?
Hydroxide
124
Water is a neutral solution because for every H+ released, an ____ is created.
OH-
125
Anything below pH 7 is an _____
Acid
126
Anything above pH 7 is an ______
Base (alkali)
127
What pH is neutral?
pH 7
128
The pH of blood is carefully maintained and balanced within what range?
7.35 - 7.45 pH
129
What is the optimum pH of the stomach?
2-3 pH
130
Why do we need the body to maintain particular pH levels?
Because it provides the perfect conditions for essential enzymes to work correctly.
131
Why might a lot of fruits and vegetables have a low pH if measured before consumption?
Because they contain organic acids.
These are metabolised by the body and intestinal bacteria to become alkaline.
132
List 3 alkaline minerals.
1. Magnesium
2. Potassium
3. Calcium
133
Before consumption, dairy is not very acidic and is also high in calcium, an alkaline mineral. So why does it have an acidic effect of the body once consumed?
Because it has a high content of protein and sulphur amino acids. These cause the formation of sulphuric acid in the body, which disrupts blood pH.
134
Why does dairy consumption cause loss of calcium leaching, even though it is high in calcium itself?
Because dairy contains a high level of sulphur amino acids. These cause formation of sulphuric acid in the body, which disrupts blood pH; drawing more alkaline calcium from the bones to neutralise the acid, and increasing calcium loss in urine.
135
Why does meat (organic or not) have an acid-forming effect on the body?
Because of its high sulphur amino acid and purines content, which causes the formation of sulphuric acid and uric acid within the body.
136
Cancer thrives in an acidic environment. It is thought that a tissue pH of ___ or above would start to kill cancer cells.
8
137
List 2 ways in which we can measure the pH of the body.
Via saliva & urine testing on litmus paper
138
When do chemical reactions occur?
When new chemical bonds are formed between molecules, or old bonds are broken.
139
Every chemical reaction involves the transfer of energy to either _______ (stored) energy, _______ energy or _____.
Potential energy, kinetic energy, or heat
140
What are 'reactants'?
The starting materials in a chemical reaction.
141
What are 'products' (in terms of chemical reactions)?
The end / resulting molecules.
142
Explain 'Collision Theory'.
For a chemical reaction to occur, there needs to be the opportunity for 2 molecules to collide.
143
What is the 'energy of activation'?
The minimum energy required for a chemical reaction
144
Name to things that can be used in a laboratory situation, to make a reaction go faster.
1. Increasing temperature
| 2. Increasing pressure
145
A catalyst helps a chemical reaction to take place with less energy required. True or false?
True
146
What does a catalyst do, and how?
Speeds up chemical reactions by lowering the activation energy required.
This means that the reaction is faster, or can occur at a lower temperature.
147
What are enzymes?
Catalysts for chemical reactions, that the body produces.
148
What is the name given to catalysts that the body produces?
Enzymes.
149
Which enzyme is involved in the production of both cholesterol and Co-enzyme Q10?
HMG-CoA reductase
150
Inhibitors act antagonistically to catalysts. True or false?
True
151
What acts antagonistically to a catalyst?
An inhibitor
152
What do inhibitors do to catalysts?
They stop the catalyst from being so effective, by making the activation energy requirement higher and slowing down the reaction time.
153
Name a type of drug that is a HMG-CoA reductase inhibitor.
Statins
154
There are 2 types of chemical reactions. Name them.
Anabolic and catabolic
155
What can be either anabolic or catabolic?
Chemical reactions
156
What is the difference between anabolic and catabolic reactions?
Anabolic reactions are building reactions. They occur when the body is making new substances / building new bonds.
Catabolic reactions are "breaking down' reactions. They occur when substances are breaking down.
157
Give an example of an anabolic reaction.
Taking amino acids and building a protein.
158
Give an example of a catabolic reaction.
Breaking down food to release ATP.
159
What is hydrolysis?
Using water to break a chemical bond
| Hydrolysis = 'water splitting'
160
What is a hydrolysis reaction?
When water is the medium that breaks down a molecule into pieces.
161
Give an example of a hydrolysis reaction.
Splitting a carbohydrate molecule into individual sugars
162
What is 'dehydration synthesis'?
When water is formed as a waste product of a reaction.
163
When water is formed as a waste product of a reaction, this is called _________ synthesis.
Dehydration
164
Give an example of dehydration synthesis.
Joining a chain of sugars together to form a long chain carbohydrate
165
Explain 'reversible reactions'.
Chemical reactions whereby the products of the reaction can react together to produce the original reactants (i.e, the chemical reaction can go both ways)
166
What are buffers?
Substances that maintain the H+ concentration in the body within normal limits
167
What is the chemical symbol for bicarbonate?
HCO3-
168
The most important buffer in the bloodstream is the ________ buffer system, which "mops up' excess acidity and maintains blood pH balance.
Bicarbonate
169
Carbon dioxide from cellular respiration reacts with water in the blood to form _________ _____
Carbonic acid
170
What are the two end products of the bicarbonate buffer system?
Carbon Dioxide and water
171
What role do the lungs play in the bicarbonate buffer system?
They exhale the resulting carbon dioxide
172
What role do the kidneys play in the bicarbonate buffer system?
They can:
a) produce the bicarbonate buffer (HCO3-)
b) they can excrete excess acidic Hydrogen ions
173
How does avoiding an acidic diet help preserve the kidneys?
The production of bicarbonate (HCO3-) by the kidneys is slow and requires a lot of effort, so avoiding adding excess acid to the body helps reduce the load on them.
174
Why do we tend to breathe harder / more rapidly when we have a build up of lactic acid?
To aid in the excretion of CO2, one of the byproducts of the bicarbonate buffer system (which is used to deal with the excess acid in the body)
175
What is 'oxidation'?
The removal of electrons from an atom / molecule
176
What is the name given to the removal of electrons from an atom or molecule?
Oxidation
177
What does oxidation do?
Reduces the potential energy in a compound
178
Generally most oxidation occurs by removing electrons with the help of hydrogen. True or false?
True
179
Name an ion involved in oxidation / reduction reactions.
Hydrogen
180
In terms of oxidation and reduction reactions, what does OIL RIG stand for?
Oxidation Is Losing (electrons)
| Reduction Is Gaining (electrons)
181
When something is 'reduced' it gains ________
Electrons
182
Why do reduction reactions result in the increase of energy in that molecule?
Because when something is 'reduced' it gains electrons.
183
Oxidation is always the loss of energy through loss of an electron. True or false?
True
184
Oxidation is the opposite of ________
Reduction
185
Reduction is the opposite of ________
Oxidation
186
What are 'free radicals'?
Molecules or compounds that have an unpaired electron in their outer shell.
187
What is the name given to molecules or compounds that have an unpaired electron in their outer shell?
Free radicals.
188
Why do free radicals cause oxidation and oxidative damage?
Because they go around stealing electrons from other stable molecules (because they have an unpaired electron in their outer shell).
189
Why can free radicals ultimately cause cancer?
Because free radicals can even take electrons from DNA, which can damage genes and therefore potentially result in cancerous changes.
190
List 4 pathologies that are closely linked to oxidative damage.
1. Cancer
2. Atherosclerosis
3. Diabetes
4. Fibromyalgia
5. Various neurodegenerative diseases, i.e, alzheimers
191
How do antioxidants work to reduce oxidative stress?
They donate an electron to free radicals, to convert them into harmless molecules, without being harmed themselves.
192
The key to a good antioxidant is that it must be stable once it has given away its electron. True or false?
True
193
List 5 common antioxidants
1. Vitamin C
2. Quercetin
3. Beta Carotene
4. Vitamin E
5. Glutathione peroxidase (an natural body antioxidant)
194
In what foods would you find beta carotene?
In orange fruit and vegetables
195
List 3 food sources of vitamin E.
1. Nuts
2. Seeds
3. Cold-pressed oils
196
List 2 food sources of quercetin.
1. Apples
| 2. Red onions
197
Antioxidant molecules are able to recycle / replenish each other. True or false?
True
198
Why might taking large doses of a single antioxidant be a bad idea?
Antioxidants don't exist in isolation in nature, because they don't work effectively in isolation. They are needed to replenish each other. This is why food sources (natural, not synthetic) of antioxidants are best.
199
Living things are characterised by molecules made from ________ and ________.
Carbon and hydrogen
200
What are 'functional groups'?
Groups of particular atoms that are attached to the carbon skeletons of molecules in living things.
201
In written biochemistry, what does R represent?
The unreactive, carbon and hydrogen part of a molecule.
202
The hydroxyl group is made up of _______ and ______ atoms
Hydrogen and oxygen
203
Alcohols belong to which biochemical functional group?
The hydroxyl group
204
The sulfhydryl group is made up of _______ and ______ atoms
Hydrogen and sulphur
205
Which functional group in biochemistry is acidic?
The carboxyl group
206
Which functional group in biochemistry is nitrogen-based?
The amine group
207
Which functional group in biochemistry is typically found on the end of amino acids and fatty acids?
The carboxyl group
208
Which functional group os found at the opposite end to a carboxyl group, in an amino acid?
The amine group
209
In biochemistry, how many functional groups are there?
6
210
In biochemistry there are 6 functional groups. List them.
1. Hydroxyl group
2. Sulfhydryl group
3. Carboxyl group
4. Amine group
5. Esters
6. Phosphates
211
Which functional group is found in triglycerides (fats?)
The Esters
212
Which functional group consists of phosphorus attached to a whole bunch of different oxygens?
The phosphates group
213
Which of the biochemical functional groups is found in the energy molecule ATP?
The phosphates
214
Give 2 functions of electrolytes in the human body.
1. Nerve & muscle function
| 2. Acid-base balance
215
Explain the role of 'buffer systems'. Name the main one.
Maintenance of pH. The main one is the bicarbonate buffer system.
216
What can create acidity in the body?
```
A high protein diet
Too much meat
Too much dairy
Stress
Insufficient exercise
```
217
What is meant by a 'biological catalyst'?
Enzymes, which facilitate chemical reactions at body temperature.
218
When water is the medium that breaks down a molecule, it is known as what type of reaction?
A hydrolysis reaction.
219
What do the terms 'oxidation' and 'reduction' mean?
Oxidation is loss of electrons
| Reduction is gaining of electrons
220
Name 2 functional groups found in all amino acids.
The amino group
| The carboxyl group
221
What biological molecule would you find an ester bond in?
In a triglyceride (fat)
222
Give a definition of 'biochemistry'.
The chemistry that goes on inside living organisms.
223
__________ include starches, cellulose and sugars.
Carbohydrates
224
All carbohydrates are made of __-__-__
C-H-O (Carbon, hydrogen, oxygen)
225
Which macronutrient has carbon atoms that are normally arranged in a ring/hexagon, with oxygen and hydrogen atoms attached?
Carbohydrates
226
Carbohydrates have a lot of ______ functional groups on them/
Hydroxyl (-OH)
227
Carbohydrates are grouped into 3 classes, depending on their size. Name these classes.
Monosaccharides
Disaccharides
Polysaccharides
228
What is the name given to single sugar (carbohydrate) units?
Monosaccharides
229
How many carbon atoms are there in a monosaccharide?
3-7
230
Name 3 types of monosaccharide.
1. Glucose
2. Galactose
3. Fructose
4. Deoxyribose
5. Ribose
231
What is the name given to 2 monosaccharides joined together by dehydration reaction?
Disaccharides
232
Where would you find the monosaccharide deoxyribose?
In DNA
233
Name 3 disaccharides.
1. Sucrose
2. Lactose
3. Maltose
234
_________ + _________ = Maltose
Glucose + glucose
235
_________ + _________ = Sucrose
Glucose + fructose
236
_________ + _________ = Lactose
Glucose + galactose
237
What is the name given to 10s - 100s of monosaccharides joined together by dehydration reaction?
Polysaccharides
238
What is the name of the storage form of carbohydrate, found in the muscles and liver? What type of carbohydrate is it?
Glycogen. A polysaccharide.
239
Name 3 types of polysaccharide
1. Glycogen
2. Cellulose
3. Starch
240
Glycogen, Starch and Cellulose are all chains of ______
Glucose
241
_________ are simple sugars that can exist as single molecules.
Monosaccharides
242
Which is the sweetest monosaccharide?
Fructose
243
Monosaccharides are grouped into families named after the number of their _____ atoms.
Carbon
244
Monosaccharides as a family are named after the amount of carbons in their molecule and arranged into 4 groups. Name these, and note the number of carbon atoms associated with each one.
Triose (3 carbons)
Pentose (5 carbons)
Hexoses (6 carbons)
Heptose (7 carbons)
245
Name 2 hexose (6 carbon atoms in the molecule) monosaccharides.
Glucose and fructose
246
The names of all __________ end in -ose.
Monosaccharides
247
What are 'isomers'?
Molecules that have the same chemical formula (same atoms) but different structures.
248
________ is the name given to molecules that have the same chemical formula but different structures.
Isomers
249
Which disaccharide is formed during the breakdown of starch?
Maltose
250
Why are polysaccharides normally insoluble in water (i.e, pasta)?
Because they're such large molecules and have given up many -OH groups.
251
What is the most common type of polysaccharide in the body?
Glycogen
252
What is our major dietary source of carbohydrate?
Starch
253
List 3 food sources of starch.
1. Bread
2. Pasta
3. Rice
254
Starch is made up of 2 different polysaccharide components. Name them.
1. Amylopectin
| 2. Amylose
255
What is the difference between amylopectin and amylose (the polysaccharide components found in starch)?
Amylose is a single, curly chain of glucose units
| Amylopectin is a multi-branched chain of glucose units, so is quicker to digest
256
Which produces a higher rise in blood sugar; amylose or amylopectin? Why?
Amylopectin.
| Because it's a multi-branched chain of glucose units that is digested quickly.
257
Which produces a higher rise in insulin; amylose or amylopectin?
Amylopectin
258
Which can provide a food source for beneficial bacteria in the intestines; amylose or amylopectin? Why?
Amylose. Because it is digested so slowly.
259
Starchy foods generally contain around __% amylopectin and around __% amylose.
75% amylopectin
| 25% amylose
260
How can we increase the beneficial amylose content in starchy foods?
By cooking them and cooling them down before eating. In this way, some of the amylopectin is converted to amylose.
261
What is 'resistant starch' in terms of food?
Starchy foods that are high in amylose.
262
Each _____ molecule is made up of about 60,000 glucose molecules.
Glycogen
263
Glycogen in which organ, can be used to help maintain blood sugar levels?
The liver
264
Why can't glycogen stored in the muscles be used to help maintain blood sugar levels?
Because it can only be used by that particular muscle.
265
What is cellulose?
A polysaccharide. The structural material of plants.
266
Where is cellulose found?
In plant cell walls.
267
Why can't humans digest cellulose, even though it is a polysaccharide made of glucose?
It has different bonds, forming a flatter, more rigid structure to its molecules. Humans lack the correct enzymes to break down these unique bonds.
268
List 2 dietary benefits of cellulose.
1. It feeds friendly gut flora
| 2. It 'sweeps' the intestine
269
Which type of macronutrient is the primary fuel for energy production?
Carbohydrates
270
List 2 reasons why carbohydrates are important in the diet.
1. They are our primary fuel for energy production.
| 2. They provide a storage form of energy (glycogen)
271
List 3 benefits of fibre (cellulose) in the diet.
1. Required for proper bowel function
2. Protects against CVD and diabetes
3. Increases satiety and weight loss
272
Glucose as an individual sugar is critical for ATP production and glycogen synthesis, but can also be turned into _______ and _____ ______.
Triglycerides and amino acids
273
Glucose is critical for the body, but we don't need to consume lots of glucose in the diet. Why is this?
Because we can create glucose from the breakdown of starches.
274
When it comes to carbohydrate digestion, everything starts in the _____.
Mouth (salivary amylase)
275
Salivary amylase, pancreatic amylase, lactase, maltase and sucrase are all enzymes involved in the digestion of ___________.
Carbohydrates
276
The last stage of carbohydrate digestion involves ______ ______ enzymes in the small intestine. These are lactase, maltase and sucrase.
Brush border enzymes
277
Where would you find the enzymes that can digest maltose, lactose and sucrose?
In the brush border of the small intestines.
278
Why can digestive pathologies such as coeliac disease lead to poor carbohydrate digestion?
Because the brush border of the small intestine is often damaged in these pathologies, which means that brush border enzymes are compromised.
279
Lipids contain 3 elements, the same as carbohydrates, but in a different ratio. Name them.
Carbon, hydrogen and oxygen
280
If lipids are hydrophobic, how do they move around our water-dense bodies?
They bond to proteins to become 'lipoproteins'.
281
____________ are the main form of dietary fat.
Triglycerides
282
Triglycerides are formed from a single _______ backbone, joined to 3 _____ _____ tails.
Glycerol backbone with 3 fatty acid chains/tails
283
List 3 reasons why we need fats / triglycerides in our diet.
1. Insulation
2. Protection of body parts (i.e, the kidneys)
3. Source of energy-dense energy
284
Why are saturated fats called saturated fats?
Because every carbon in their backbone has a maximum number of bonds to a hydrogen.
Each carbon atom is saturated with hydrogen atoms.
285
________ fats are generally solid at room temperature.
Saturated
286
________ fats are very straight molecules
Saturated
287
________ fats are kinked / v-shaped molecules
Monounsaturated
288
________ fats are generally liquid at room temperature.
Monounsaturated
289
Monounsaturated fats contain fatty acids with __ double covalent bond between 2 carbons.
1
290
In terms of molecular structure, what is the difference between monounsaturated and polyunsaturated fats?
Monounsaturated fats have 1 double covalent bond between 2 carbons. So they have a kink in their chain.
Polyunsaturated fats have more than one double bond in their carbon chain, so have multiple kinks.
291
Give a food example of a polyunsaturated fat.
Sunflower oil
Rapeseed oil
Vegetable oil
Nuts & seeds in whole food form
292
Give a food example of a monounsaturated fat.
Olive oil
293
Give a food example of a saturated fat.
Coconut oil, butter, lard, meat fat.
294
The end of a fatty acid chain is always the end without the ______
Oxygens.
i.e, the end furthest away from the carboxyl functional group
295
Fatty acids are named according to the closest double bond to the end of the chain. So...
In Omega 3 fatty acids, the double bond is ___ carbon molecules from the end of the chain.
In Omega 6 fatty acids, the double bond is ___ carbon molecules from the end of the chain.
Omega 3 = double bond is 3 carbon molecules from the end of the chain.
Omega 6 = double bond is 6 carbon molecules from the end of the chain.
296
Wherever we have a double carbon bond in a fatty acid, there are 2 possibility of where the hydrogens can go. True or false?
True
297
The hydrogen atoms are found on the same side as the double carbon bond in the configuration of ____ fatty acids.
Cis
298
The hydrogen atoms are found on opposite sides of the double carbon bond in the configuration of ____ fatty acids.
Trans
299
In nature, do nearly all fats have a cis or trans structure?
Cis
300
Do our bodies recognise and easily use cis or trans fats?
Cis fats
301
Explain the difference between cis and trans fats.
Cis fats have hydrogen atoms on the same side as their double carbon bond, whereas trans fats have hydrogen atoms on opposite sites of their double carbon bond.
Nearly all fats found in nature are cis fats. These are more easily recognised and utilised by the body.
302
Trans fats are found in industrially synthesised fats. True or false?
True
303
____ fats have a nice kink in their molecule structure, whilst ___ fats are straighter and more rigid.
Cis fats = kinked
| Trans fats = straight and rigid
304
____ fats make cell membranes more flexible.
Cis
305
____ fats make cell membranes more stiff, making them more leaky and prone to oxidative damage.
Trans
306
Which industry process helps to make vegetable oils more solid?
Hydrogenation
307
Explain how cis fats are turned into trans fats.
By heating to high temperatures, or heating oil repeatedly.
(The hydrogen on the double carbon bond spins around).
308
What are essential fatty acids (EFA's)?
EFA's are polyunsaturated fatty acids that can't be constructed within the body, and therefore must be obtained from the diet.
309
Can the human body make essential fatty acids (EFA's)?
No
310
Are essential fatty acids (EFA's) saturated, monounsaturated or polyunsaturated fats?
Polyunsaturated
311
Name the 2 families of EFA's.
Omega 3's and Omega 6's
312
As well as Omega 3 and Omega 6, there are other omega fatty acids but they're not essential to human health. True or false?
True
313
Name 3 food sources of EFA's.
1. Nuts
2. Seeds
3. Oily fish
314
Which Omega fatty acid family does alpha-linolenic acid belong to?
Omega 3
315
Which Omega fatty acid family does linoleic acid belong to?
Omega 6
316
Which fatty acid family includes ALA, EPA and DHA
Omega 3's
317
Which fatty acid family includes LA, GLA and AA
Omega 6's
318
The Omega 3 fatty acid ALA, can be converted into the other omega 3 fatty acids EPA and DHA in the body. True or false?
True
319
The Omega 6 fatty acid LA, can be converted into the other omega 6 fatty acids GLA and AA in the body. True or false?
True
320
Name 3 food sources of the Omega 6 fatty acid Arachadonic Acid.
1. Meat
2. Dairy products
3. Eggs
321
Name 3 food sources of Alpha-linolenic acid (ALA, Omega 3)
1. Walnuts
2. Green leafy vegetables
3. Flaxseeds
322
Name 1 food source of EPA & DHA (Omega 3)
Oily fish
323
Name 2 food sources of linoleic acid (LA, Omega 6)
1. Most nuts and seeds
| 2. Vegetable oils
324
Is evening primrose oil an omega 3 or omega 6 fatty acid?
Omega 6 (GLA)
325
Why is it important to eat a variety of well-sourced omega 3 and 6 fatty acids?
To help give cell membranes both flexibility (omega 3) and structure (omega 6).
326
The conversion of ALA to EPA and DHA, and the conversion of LA to GLA and AA, requires ________ enzymes.
Desaturase enzymes
327
List 5 functions of Essential Fatty Acids (EFA's).
1. Fluidity and structure of cell membranes
2. Synthesis of prostaglandins
3. Formation of haemoglobin
4. Support the production of digestive enzymes
5. Help transport cholesterol in the blood.
328
List 3 things that can accelerate oxidation and the formation of free radicals, when it comes to polyunsaturated fats.
1. Light
2. Oxygen
3. Heat
329
To cook with, you should use ________ fats. This is because they are stable at high temperatures.
Saturated fats (no double carbon bonds, so more stable)
330
How should unsaturated fats be stored?
In dark glass bottles, in a dark place, in the fridge once opened.
331
What is a lipoprotein and what is its purpose?
A fat molecule that has been joined to a protein molecule.
Lipoproteins enable lipids to move around easily in the bloodstream.
(Remember that fats on their own are hydrophobic).
332
What would you find inside a lipoprotein?
Triglycerides and cholesterol
333
Lipoproteins are synthesised by which organ?
The liver
334
Name the 4 types of lipoproteins.
1. Chylomicrons
2. Very Low Density Lipoproteins (VLDLs)
3. Low Density Lipoproteins (LDLs)
4. High Density Lipoproteins (HDLs)
335
Very Low Density Lipoproteins (VLDLs) are used to carry newly-synthesised triglycerides from the ______ to the ______ tissue.
From the liver to adipose tissue
336
Which form of lipoprotein if high, indicates over-eating?
VLDLs
337
Low Density Lipoproteins (LDLs) are used to carry ______ from the ______ to the cells of the body.
Cholesterol from the liver to the cells
338
Which type of lipoprotein collects cholesterol from the body's tissues and brings it back to the liver?
HDLs
339
_______ is needed to repair cells, support cell membranes and synthesise sex and adrenal hormones.
Cholesterol
340
Phospholipids contain a ________, 2 _____ _____ tails and a phosphate head.
A glycerol molecule, 2 fatty acid tails...
341
What is the name given to lipids that are formed from cholesterol?
Steroids
342
What are steroids?
Lipids that are formed from cholesterol
343
Why don't we need to eat cholesterol?
Because our liver can produce it.
344
Name 3 hormones created from steroids ('steroid hormones').
1. Oestrogen
2. Testosterone
3. Cortisol
345
Which type of lipid is formed from 4 rings of carbon atoms, joined at their base?
Steroids
346
Name 2 monosaccharides.
1. Glucose
2. Fructose
3. Galactose
347
Explain what is meant by an isomer.
Something that is made of the same atoms (chemical formula) but which has a different chemical structure. i.e, glucose and fructose
348
What is the name of the type of bond between two monosaccharides?
Glycosidic bond (formed by dehydration synthesis).
349
Which digests faster - amylose or amylopectin? Why?
Amylopectin. Because it has a branching structure
350
Where is glycogen stored?
In the liver and muscles
351
Why are lipids hydrophobic?
Because they have very few polar bonds (unlike water).
352
Which types of fat are prone to oxidation?
Polyunsaturated fats
