Chapter 2: chemical organization Flashcards
Introduce the language and fundamental concepts of chemistry as it relates to the human body. Discuss how chemical bonds form and how chemical reactions occur Compare and contrast organic and inorganic compounds Describe the structure, function and importance of the four main groups of macromolecules (carbohydrates, lipids, proteins and nucleic acids) (185 cards)
1
Q
What chemical element constitutes the largest percentage of total body mass in humans?
A
Oxygen (O) - About 65% of total body mass.
1
Q
What is the significance of oxygen in the human body?
A
Oxygen is crucial for cellular respiration, enabling the production of energy (ATP) from nutrients. It is also a major component of water and organic molecules.
2
Q
Which element plays a major role in bone formation and makes up a significant percentage of total body mass?
A
Calcium (Ca) - About 1.5%. It is essential for the formation of bones and teeth, as well as muscle function, nerve signaling, and blood clotting.
3
Q
What is the role of nitrogen in the human body, and what percentage of body mass does it comprise?
A
Nitrogen (N) - About 3%. It is a key component of amino acids, proteins, and nucleic acids like DNA and RNA.
4
Q
Which element is vital for the transport of oxygen in blood and is found in hemoglobin?
A
Iron (Fe) - It makes up less than 0.01% of body mass but is crucial for oxygen transport in hemoglobin and myoglobin.
5
Q
Name the chemical element that is a key component of DNA and ATP, and indicate its percentage of body mass.
A
Phosphorus (P) - About 1%. Phosphorus is critical for the structure of DNA, RNA, and ATP, and is also important in the formation of bones and teeth.
6
Q
significance of carbon in the body:
A
Forms backbone chains and rings of all organic molecules: carbohydrates, lipids (fats), proteins, and nucleic acids (D N A and R N A).
7
Q
significance of hydrogen in the body:
A
constituent of water and most organic molecules; ionized form (H+) makes body fluids more acidic.
8
Q
What are chemical elements?
A
Chemical elements are building blocks of matter, both living and nonliving, that cannot be split into simpler substances by ordinary chemical means.
9
Q
How many chemical elements are normally present in the human body?
A
Twenty-six different chemical elements are normally present in the human body.
10
Q
What percentage of the body’s mass is made up of major elements?
A
Major elements make up about 96% of the body’s mass.
11
Q
Which four elements are considered the major elements in the human body?
A
Oxygen, carbon, hydrogen, and nitrogen.
12
Q
What are the lesser elements, and what percentage of the body’s mass do they make up?
A
The lesser elements are calcium, phosphorus (P), potassium (K), sulfur (S), sodium, chlorine (Cl), magnesium (Mg), and iron (Fe). They make up about 3.6% of the body’s mass.
13
Q
How much of the body’s mass is made up by trace elements?
A
Trace elements account for about 0.4% of the body’s mass.
14
Q
How many trace elements are present in the human body?
A
There are 14 trace elements present in the human body.
15
Q
Potassium significance (K):
A
0.35 % of total body mass; needed to generate action potentials.
16
Q
Sulfur (S) significance:
A
0.25 % of TBM; Component of some vitamins and many proteins.
17
Q
Sodium (Na) significance:
A
0.2 % of TBM; the most plentiful cation in extracellular fluid; essential for maintaining water balance; needed to generate action potentials.
18
Q
Chlorine (Cl) significance:
A
0.2 % of TBM; the most plentiful anion (negatively charged particle) in extracellular fluid; essential for maintaining water balance.
19
Q
Significance of Magnesium (Mg):
A
o.1 % of TBM; needed for action of many enzymes (molecules that increase the rate of chemical reactions in organisms).
20
Q
When do chemical reactions occur?
A
when new bonds are formed, or old bonds are broken
21
Q
what is a reactant?
A
starting substances
22
Q
what is a product?
A
ending substances
23
Q
What happens to bonds during a chemical reaction?
A
Old bonds break and new bonds form between atoms.
24
What is the relationship between the number of atoms before and after a chemical reaction?
The number of atoms of each element is the same before and after a chemical reaction.
25
In the reaction between hydrogen and oxygen, what are the reactants?
The reactants are two hydrogen molecules (H2) and one oxygen molecule (O2).
26
What are the products of the chemical reaction between hydrogen and oxygen?
The products are two molecules of water (H2O).
27
What does the arrow in a chemical reaction represent?
The arrow indicates the direction in which the reaction proceeds.
28
How is the mass of the reactants related to the mass of the products in a chemical reaction?
The total mass of the reactants equals the total mass of the products.
29
Why do the reactants and products have different chemical properties?
The atoms are rearranged during the chemical reaction, leading to different chemical properties for the reactants and products.
30
What is metabolism?
Metabolism refers to all the chemical reactions occurring in the body.
31
What is energy?
Energy is the capacity to do work.
32
What are the two principal forms of energy?
Potential energy (stored energy) and kinetic energy (energy in motion).
33
What is potential energy?
Potential energy is stored energy, like the energy in water behind a dam or a person poised to jump.
34
What happens to potential energy when it is released?
It is converted into kinetic energy.
35
What is chemical energy?
Chemical energy is a form of potential energy stored in the bonds of compounds and molecules.
36
What does the law of conservation of energy state?
Energy can neither be created nor destroyed, but it can be converted from one form to another.
37
How is the chemical energy in food used by the body?
It is converted into kinetic energy for activities like walking and talking.
38
What generally happens when energy is converted from one form to another?
Some energy is released as heat, which helps maintain normal body temperature.
39
What do chemical bonds represent?
Chemical bonds represent stored chemical energy.
40
What happens during a chemical reaction?
New bonds are formed or old bonds are broken between atoms.
41
What is an exergonic reaction?
An exergonic reaction releases more energy than it absorbs.
42
What is an endergonic reaction?
An endergonic reaction absorbs more energy than it releases.
43
What is activation energy?
Activation energy is the energy needed to start a chemical reaction.
44
How is energy released during a chemical reaction?
As new bonds form during the reaction, energy is released to the surroundings.
45
What are the two factors that influence activation energy?
Concentration of particles and temperature.
46
How does concentration affect the chance of a collision in a chemical reaction?
The higher the concentration of particles, the more likely they are to collide and cause a reaction.
47
How does temperature affect the movement of particles in a chemical reaction?
Higher temperature increases the speed of particles, making collisions more forceful and increasing the chance of a reaction.
48
What happens during a chemical reaction?
Particles collide and bonds either break or form.
49
Why can't the body rely solely on temperature and molecule concentration to speed up reactions?
Raising temperature or concentration could damage cells.
50
What is a catalyst?
A catalyst speeds up a reaction by lowering the activation energy needed for a successful reaction.
51
How does a catalyst affect the energy difference between reactants and products?
A catalyst does not change the energy difference between reactants and products.
52
How does a catalyst help in a chemical reaction? (I.e: make reactions more efficient).
A catalyst ensures that particles collide in the correct orientation, making the reaction more efficient.
53
Does a catalyst get used up during a reaction?
No, a catalyst remains unchanged and can be reused for multiple reactions.
54
In the reaction A + B + C → AB + C, what role does C play?
C is the catalyst, as it is not used up in the reaction.
55
What are most catalysts in living cells called?
Most catalysts in living cells are protein molecules called enzymes.
56
What are the two parts of some enzymes?
The protein portion is called the apoenzyme, and the nonprotein portion is called the cofactor.
57
How do enzymes work?
Enzymes catalyze specific reactions with great efficiency by binding only to specific substrates, fitting like a key in a lock or adjusting shape around the substrate (induced fit).
58
What is the specificity of enzymes?
Each enzyme is highly specific, binding only to particular substrates and producing specific products.
59
How much can enzymes speed up reactions?
Enzymes can speed up reactions by 100 million to 10 billion times compared to reactions without them.
60
How many substrate molecules can a single enzyme convert into products per second under optimal conditions?
A single enzyme can convert between 1 to 600,000 substrate molecules into products per second under optimal conditions.
61
How is enzyme production and concentration controlled?
Enzyme production and concentration are controlled by cellular genes.
62
What can influence enzyme activity within a cell and how do enzymes exist?
Enzyme activity can be enhanced or inhibited by substances within the cell, and enzymes can exist in active or inactive forms depending on the cell's chemical environment.
63
what do enzymes serve as?
catalysts that regulate the speed of chemical reactions.
64
what is and important factor to regulate enzyme activity?
Temperature. Individual enzymes have an optimal temperature at which they are most active.
65
What do chemical bonds represent in terms of energy?
Chemical bonds represent stored chemical energy.
66
What happens during a chemical reaction?
Chemical reactions occur when new bonds are formed, or old bonds are broken between atoms.
67
What is the difference between exergonic and endergonic reactions?
Exergonic reactions release more energy than they absorb, whereas endergonic reactions absorb more energy than they release.
68
What happens in the body’s metabolism regarding exergonic and endergonic reactions?
In the body’s metabolism, exergonic reactions and endergonic reactions are coupled, where energy released from exergonic reactions is used to drive endergonic reactions.
69
What typically happens during exergonic reactions in terms of nutrients?
Exergonic reactions typically occur when nutrients, such as glucose, are broken down.
70
What is a synthesis reaction?
A synthesis reaction is a process where two or more atoms, ions, or molecules combine to form new and larger molecules.
71
What does the word 'synthesis' mean?
The word 'synthesis' means "to put together."
72
What are all the synthesis reactions in the body collectively called?
All the synthesis reactions in the body are collectively referred to as anabolism.
73
Are anabolic reactions typically exergonic or endergonic? Why?
Anabolic reactions are usually endergonic because they absorb more energy than they release.
74
Can you give an example of an anabolic reaction?
An example of an anabolic reaction is the combination of simple molecules like amino acids to form large molecules such as proteins.
75
What happens during a decomposition reaction?
During a decomposition reaction, large molecules are split into smaller atoms, ions, or molecules.
76
What are the decomposition reactions in the body collectively called?
The decomposition reactions in the body are collectively referred to as catabolism.
77
Are catabolic reactions typically exergonic or endergonic? Why?
Catabolic reactions are usually exergonic because they release more energy than they absorb.
78
Can you give an example of a catabolic reaction?
An example of a catabolic reaction is the series of reactions that break down glucose to pyruvic acid, which produces a net gain of two molecules of ATP.
79
What is the sum of all anabolic and catabolic reactions in the body called?
The sum of all anabolic and catabolic reactions in the body is referred to as metabolism.
80
What do carbohydrates include?
Carbohydrates include sugars, glycogen, starches, and cellulose.
81
What percentage of total body mass do carbohydrates represent in humans?
Carbohydrates represent only 2-3% of total body mass in humans.
82
What is the primary function of carbohydrates in humans and animals?
The primary function of carbohydrates in humans and animals is to serve as a source of chemical energy for generating ATP needed to drive metabolic reactions.
83
What is an example of a carbohydrate used for building structural units, and in what molecule is it found?
An example of a carbohydrate used for building structural units is deoxyribose, a type of sugar found in DNA, the molecule that carries inherited genetic information.
84
What elements are found in carbohydrates, and what is the typical ratio of hydrogen to oxygen atoms?
Carbohydrates contain carbon, hydrogen, and oxygen, with a typical hydrogen to oxygen ratio of 2:1, the same as in water.
85
What are the three major groups of carbohydrates based on their sizes?
The three major groups of carbohydrates based on their sizes are monosaccharides, disaccharides, and polysaccharides.
86
What is the main source of energy needed for life?
Carbohydrates are the main source of energy needed for life.
87
What are monosaccharides?
Monosaccharides are the basic units of carbohydrates. (simple sugars).
88
How many carbon atoms do monosaccharides typically contain?
Monosaccharides typically contain 3 to 7 carbon atoms.
89
examples of monosaccharides:
Glucose (the main blood sugar).
Fructose (found in fruits).
Galactose (in milk sugar).
Deoxyribose (in DNA).
Ribose (in RNA).
90
How are monosaccharides named?
Monosaccharides are named with the suffix "-ose" and prefixes that indicate the number of carbon atoms they contain, such as trioses (3 carbons), tetroses (4 carbons), pentoses (5 carbons), hexoses (6 carbons), and heptoses (7 carbons).
91
What is an example of a hexose, and what is its role in the cell?
An example of a hexose is glucose, which is broken down by cells to produce energy in the form of ATP.
92
How are disaccharides formed?
Disaccharides are formed by combining two monosaccharides through dehydration synthesis, which involves the removal of a water molecule.
93
What is an example of a disaccharide, and how is it formed?
An example of a disaccharide is sucrose, which is formed by combining glucose and fructose.
94
What are isomers, and how do glucose and fructose fit this description?
Isomers are compounds that share the same chemical formula but differ in the arrangement of atoms, affecting their chemical properties. Glucose and fructose are isomers because they have the same formula but different atom arrangements.
95
Examples of disaccharides:
Sucrose (table sugar) = glucose + fructose.
Lactose (milk sugar) = glucose + galactose.
Maltose = glucose + glucose.
96
What are polysaccharides comprised of?
Polysaccharides are comprised of tens or hundreds of monosaccharides linked by dehydration synthesis.
97
What are the typical properties of polysaccharides regarding solubility and taste?
Polysaccharides are typically insoluble in water and are not sweet.
98
What is glycogen, and where is it stored in the human body?
Glycogen is a polysaccharide stored in the human liver and skeletal muscles.
99
What is the function of glycogen in the body?
Glycogen is broken down into glucose when blood sugar is low to provide energy (ATP).
100
What are starches, and where are they found?
Starches are polysaccharides formed by plants from glucose, found in foods like pasta and potatoes, and are a key part of the human diet.
101
How can polysaccharides be broken down, and what does this process yield?
Like disaccharides, polysaccharides can be hydrolyzed into monosaccharides, such as glucose.
102
What is cellulose, and what role does it play in the human body?
AKA fiber; part of cell walls in plants that cannot be digested by humans but aids movement of food through intestines
103
What are lipoproteins?
Particles made of fat and protein that transport cholesterol, triglycerides, and other fats through the bloodstream.
104
Why are lipoproteins important?
They help carry non-water-soluble fats around the body for energy storage, hormone production, and cell structure.
105
What is LDL and why is it considered bad cholesterol?
Low-Density Lipoprotein; it can clog arteries leading to cardiovascular issues.
106
What role does HDL play in cholesterol management?
High-Density Lipoprotein helps clean up cholesterol from the bloodstream, making it good cholesterol.
107
What does VLDL do?
Very Low-Density Lipoprotein carries triglycerides from the liver to tissues and can contribute to plaque buildup in arteries.
108
What are fatty acids?
Simple lipids used to synthesize triglycerides and phospholipids, and they can be catabolized to generate ATP.
109
What are the components of a fatty acid?
A carboxyl group and a hydrocarbon chain.
110
What distinguishes saturated fatty acids from unsaturated fatty acids?
Saturated fatty acids contain only single covalent bonds between carbon atoms, while unsaturated fatty acids have one or more double bonds.
111
What defines a saturated fatty acid?
contains only single covalent bonds between the carbon atoms in the hydrocarbon chain.
112
What does it mean for a saturated fatty acid to be "saturated with hydrogen"?
Each carbon atom in the hydrocarbon chain is fully bonded to hydrogen atoms due to the absence of double bonds.
113
What characterizes an unsaturated fatty acid?
It contains one or more double covalent bonds between carbon atoms, resulting in less hydrogen saturation.
114
What happens to the shape of an unsaturated fatty acid at the site of a double bond?
It creates a kink (bend) in the hydrocarbon chain.
115
What is a monounsaturated fatty acid?
A fatty acid with one double bond in its hydrocarbon chain, resulting in one kink.
116
What is a polyunsaturated fatty acid?
A fatty acid with more than one double bond in its hydrocarbon chain, resulting in multiple kinks.
117
What are omega-3 fatty acids?
Polyunsaturated fatty acids found in flax, canola and olive oils, and seafood.
118
Name the three main types of omega-3 fatty acids.
EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and ALA (α-linolenic acid).
119
What is one health benefit of omega-3 fatty acids?
They help decrease inflammation in the body.
120
How do omega-3 fatty acids affect muscle protein synthesis?
They increase muscle protein synthesis pathways.
121
What effect do omega-3 fatty acids have on oxygen delivery during exercise?
They increase oxygen delivery to the heart during exercise.
122
In what way do omega-3 fatty acids enhance nervous system function?
They increase nerve conduction velocity.
123
What are fatty acids?
Building blocks of fats in our diet, categorized into saturated and unsaturated fatty acids.
124
What defines saturated fatty acids?
They have no double bonds between their carbon atoms.
125
Name some common sources of saturated fatty acids.
Red meat, butter, cheese, and whole milk.
126
Provide an example of a saturated fatty acid.
Palmitic acid.
127
What characterizes unsaturated fatty acids?
They have one or more double bonds in their structure.
128
Why are unsaturated fats considered healthier than saturated fats?
They are generally associated with better health outcomes, including reduced risk of heart disease.
129
What are monounsaturated fatty acids?
Unsaturated fatty acids that contain one double bond.
130
Name some sources of monounsaturated fatty acids.
Olive oil, canola oil, peanut oil, nuts, and avocados.
131
Provide an example of a monounsaturated fatty acid.
Oleic acid.
132
What are polyunsaturated fatty acids?
Unsaturated fatty acids that contain more than one double bond.
133
What are omega-6 fatty acids?
A subtype of polyunsaturated fatty acids with the first double bond between the 6th and 7th carbon atoms.
134
Name some sources of omega-6 fatty acids.
Corn oil, soybean oil, and nuts.
135
Provide an example of an omega-6 fatty acid.
Linoleic acid
136
What are omega-3 fatty acids?
A subtype of polyunsaturated fatty acids with the first double bond between the 3rd and 4th carbon atoms.
137
Provide an example of an omega-3 fatty acid.
Alpha-linolenic acid (ALA).
138
Fatty acids function:
Used to synthesize triglycerides and phospholipids or catabolized to generate adenosine triphosphate (ATP).
139
Triglycerides (fats and oils) functions:
Protection, insulation, energy storage.
140
what are the most plentiful lipids in your body?
triglycerides
141
what "building blocks" do triglycerides consist of?
a single glycerol molecule and three fatty acid molecules.
142
what is the major form of lipid in food and in the body?
Triglycerides
143
What are triglycerides?
Lipids that can be either solids or liquids at room temperature.
144
what do triglycerides primarily consist of?
primarily consisting of saturated fatty acids.
145
Why can saturated fatty acids solidify at room temperature?
They lack double bonds in their hydrocarbon chains, allowing them to closely pack together.
146
Why do unsaturated fatty acids prevent oils from solidifying?
Unsaturated fatty acids contain one or more double bonds, creating kinks that prevent close packing.
147
What types of fatty acids can be found in oils?
Oils can contain either monounsaturated or polyunsaturated fatty acids.
148
What are monounsaturated fats?
Triglycerides that mostly consist of monounsaturated fatty acids.
149
What are polyunsaturated fats?
Triglycerides that mostly consist of polyunsaturated fatty acids.
150
In what form is fat primarily stored in humans?
As triglycerides, which are composed of three fatty acids attached to a glycerol backbone.
151
How much energy does 1 gram of fat (triglycerides) provide?
Approximately 9 kilocalories (kcal) of energy.
152
How does the energy content of fat compare to carbohydrates and proteins?
Fat provides more than twice the energy, with carbohydrates and proteins yielding about 4 kcal per gram.
153
Where are triglycerides stored in the body?
In adipose tissue.
154
What is the role of triglycerides in the body?
They serve as the body's long-term energy reserve, usable when immediate energy from carbohydrates is unavailable.
155
How much energy is stored in a pound of body fat?
Roughly 3,500-3,600 kcal of energy.
156
When are the body's fat stores particularly important?
During periods of fasting, extended exercise, or calorie restriction.
157
What are phospholipids?
Molecules similar to triglycerides but with a different structure, consisting of a glycerol backbone, two fatty acid chains, and a phosphate group.
158
How do the structures of phospholipids and triglycerides differ?
Phospholipids have a phosphate group with a charged group instead of a third fatty acid chain.
159
What does it mean for phospholipids to be amphipathic?
They have both a polar (hydrophilic) and a nonpolar (hydrophobic) region.
160
How do phospholipids arrange themselves in a cell membrane?
They align in a dual-layered structure (bilayer), with the tails facing inward and the heads facing outward, creating a barrier.
161
What is the "head" of a phospholipid?
The polar part of the molecule that includes the phosphate group and can interact with water.
162
what are the important components of cell membranes?
phospholipids
163
function of cholesterol in the body as a steroid:
Minor component of all animal cell membranes; precursor of bile salts, vitamin D, and steroid hormones
164
function of Bile Salts in the body as a steroid:
Needed for digestion and absorption of dietary lipids.
165
function of Vitamin D in the body as a steroid:
Helps regulate calcium level in body; needed for bone growth and repair.
166
function of Adrenocortical in the body as a steroid:
- regulate metabolism
- resistance to stress
- salt and water balance.
167
function of sex hormones in the body as a steroid:
Stimulate reproductive functions and sexual characteristics.
168
What is the basic structure of steroids?
Four interconnected carbon rings.
169
How do steroids differ from triglycerides?
Steroids do not have a glycerol backbone and fatty acid chains.
170
From what are steroids synthesized in the body?
Cholesterol
171
What regions do steroids contain?
A large nonpolar region with carbon rings and a hydrocarbon tail.
172
What is the role of cholesterol in the body?
It maintains cell membrane integrity and is a precursor for other steroids.
173
What are the functions of estrogens and testosterone?
They regulate sexual development and reproductive functions.
174
What is cortisol involved in?
It helps in stress response, maintains blood sugar levels, regulates metabolism, and reduces inflammation.
175
What are bile salts derived from?
Cholesterol; they help emulsify and absorb dietary fats.
176
How is vitamin D synthesized?
From cholesterol when the skin is exposed to sunlight.
177
What is a key characteristic of sterols?
They contain at least one hydroxyl group (—OH), providing weak amphipathic properties.
178
What are anabolic steroids?
Synthetic variations of steroids used to enhance muscle mass, strength, and endurance
179
What is the function of triglycerides in the body?
Energy storage, insulation, and protection.
180
What role do phospholipids play in cells?
Forming the cell membrane and maintaining its integrity as a bilayer.
181
How do steroids function in organisms?
They act as signaling molecules and contribute to maintaining membrane fluidity and structure.
182
What function do glycolipids serve in cells?
They assist in cell recognition and provide energy.
183
What are the monomers of proteins?
Amino Acids
184
How many different amino acids exist?
20
