Chapter 2 Flashcards
1
Q
What is chemistry’s role in physiological reactions?
A
Chemistry underlies all physiological reactions, including movement, digestion, heart pumping, and nervous system activity.
2
Q
What are the two main divisions of chemistry?
A
Basic chemistry and biochemistry.
3
Q
What is matter?
A
Matter is anything that has mass and occupies space.
4
Q
What are the three states of matter?
A
Solid (definite shape and volume), Liquid (changeable shape, definite volume), Gas (changeable shape and volume).
5
Q
What is energy?
A
Energy is the capacity to do work or put matter into motion.
6
Q
What are the two forms of energy?
A
Kinetic (energy in action) and Potential (stored energy).
7
Q
What are the four types of energy?
A
Chemical energy, Electrical energy, Mechanical energy, and Radiant energy.
8
Q
How is energy converted?
A
Energy can be transformed from one form to another, but some energy is always lost as heat.
9
Q
What are elements?
A
Elements are substances that cannot be broken down into simpler substances by ordinary chemical methods.
10
Q
What four elements make up 96% of the human body?
A
Carbon, Oxygen, Hydrogen, and Nitrogen.
11
Q
What are atoms?
A
Atoms are the building blocks of elements.
12
Q
What are the three subatomic particles in an atom?
A
Protons (positive charge), Neutrons (neutral charge), Electrons (negative charge).
13
Q
What is the atomic number?
A
The number of protons in an atom’s nucleus.
14
Q
What is atomic mass?
A
The sum of protons and neutrons in an atom’s nucleus.
15
Q
What are isotopes?
A
Atoms of the same element that have different numbers of neutrons.
16
Q
What is a molecule?
A
A molecule is two or more atoms bonded together.
17
Q
What is a compound?
A
A compound is a molecule that contains at least two different types of atoms.
18
Q
What are the three types of mixtures?
A
Solutions, Colloids, and Suspensions.
19
Q
What are solutions?
A
Homogeneous mixtures where solutes are evenly distributed in a solvent.
20
Q
What are colloids?
A
Heterogeneous mixtures where particles do not settle out (e.g., Jell-O).
21
Q
What are suspensions?
A
Heterogeneous mixtures where large particles settle out (e.g., blood).
22
Q
What are chemical bonds?
A
Energy relationships between electrons of reacting atoms.
23
Q
What is the octet rule?
A
Atoms strive to have eight electrons in their valence shell.
24
Q
What are the three types of chemical bonds?
A
Ionic bonds, Covalent bonds, and Hydrogen bonds.
25
What are ionic bonds?
Bonds formed by the transfer of electrons, resulting in charged ions.
26
What are covalent bonds?
Bonds formed by the sharing of electrons.
27
What are polar and nonpolar covalent bonds?
Polar bonds involve unequal sharing of electrons, while nonpolar bonds involve equal sharing.
28
What are hydrogen bonds?
Weak attractions between slightly positive hydrogen and slightly negative atoms.
29
What is biochemistry?
The study of chemical composition and reactions in living matter.
30
What are inorganic compounds?
Compounds that do not contain carbon (e.g., water, salts, acids, and bases).
31
What are organic compounds?
Compounds that contain carbon and are covalently bonded (e.g., carbohydrates, lipids, proteins, nucleic acids).
32
Why is water important in biological systems?
It has high heat capacity, high heat of vaporization, polarity, reactivity, and cushioning properties.
33
What are carbohydrates?
Sugars and starches composed of carbon, hydrogen, and oxygen.
34
What are the three types of carbohydrates?
Monosaccharides (single sugars), Disaccharides (two sugars), and Polysaccharides (many sugars).
35
What are lipids?
Fats and oils that are hydrophobic and store energy.
36
What are the main types of lipids?
Triglycerides, Phospholipids, Steroids, and Eicosanoids.
37
What are proteins?
Molecules composed of amino acids that perform various biological functions.
38
What are the four levels of protein structure?
Primary, Secondary, Tertiary, and Quaternary.
39
What are enzymes?
Proteins that act as biological catalysts to speed up chemical reactions.
40
What are nucleic acids?
DNA and RNA, which store and transfer genetic information.
41
What are the building blocks of nucleic acids?
Nucleotides (composed of a nitrogen base, a pentose sugar, and a phosphate group).
42
What are the differences between DNA and RNA?
DNA is double-stranded and contains thymine, while RNA is single-stranded and contains uracil.
43
What is ATP?
Adenosine triphosphate, the energy currency of cells.
44
How does ATP provide energy?
ATP releases energy when its phosphate bonds are broken.
45
What is the main difference between organic and inorganic compounds?
Organic compounds contain carbon and are usually covalently bonded; inorganic compounds do not contain carbon.
46
What are the key properties of water that make it essential for life?
High heat capacity, high heat of vaporization, polarity, solvent properties, reactivity, and cushioning.
47
What is hydrolysis?
A chemical reaction that breaks down compounds by adding water.
48
What is dehydration synthesis?
A chemical reaction that joins molecules by removing water.
49
What are electrolytes?
Substances that dissociate into ions in solution and conduct electricity.
50
What is the role of calcium in the body?
Essential for bone health, muscle contraction, nerve transmission, and blood clotting.
51
What are trace elements?
Elements required in very small amounts for biological processes (e.g., iron, zinc, copper).
52
What is the primary function of hemoglobin?
To transport oxygen in the blood.
53
What is the main role of myoglobin?
To store oxygen in muscle tissues.
54
What are free radicals?
Highly reactive molecules with unpaired electrons that can damage cells.
55
What is an antioxidant?
A molecule that neutralizes free radicals to prevent cellular damage.
56
What is an emulsifier?
A substance that stabilizes mixtures of oil and water, such as bile in digestion.
57
What is osmosis?
The passive movement of water across a semipermeable membrane.
58
What is diffusion?
The movement of molecules from a higher concentration to a lower concentration.
59
What is facilitated diffusion?
The movement of molecules across a membrane with the help of transport proteins.
60
What is active transport?
The movement of substances against their concentration gradient using energy (ATP).
61
What is an isotonic solution?
A solution with the same solute concentration as the inside of a cell, resulting in no net water movement.
62
What is a hypotonic solution?
A solution with a lower solute concentration than inside the cell, causing water to enter and the cell to swell.
63
What is a hypertonic solution?
A solution with a higher solute concentration than inside the cell, causing water to leave and the cell to shrink.
64
What is an enzyme-substrate complex?
The temporary binding of an enzyme to its specific substrate during a reaction.
65
What is a coenzyme?
A non-protein molecule that helps an enzyme function, often derived from vitamins.
66
What is a cofactor?
A metal ion or molecule that assists enzyme function.
67
What is feedback inhibition?
A regulatory mechanism where the end product of a pathway inhibits an earlier enzyme to control its production.
68
What is the function of ribosomes?
Ribosomes are responsible for protein synthesis.
69
What is the function of the rough endoplasmic reticulum?
It assists in protein synthesis and modification.
70
What is the function of the smooth endoplasmic reticulum?
It is involved in lipid synthesis and detoxification.
71
What is the role of the Golgi apparatus?
It modifies, sorts, and packages proteins and lipids for transport.
72
What is exocytosis?
The process by which vesicles transport materials out of the cell.
73
What is endocytosis?
The process by which the cell engulfs materials from its environment.
74
What is pinocytosis?
A type of endocytosis where the cell engulfs extracellular fluid.
75
What is phagocytosis?
A type of endocytosis where the cell engulfs large particles like bacteria.
76
What is apoptosis?
Programmed cell death that helps maintain homeostasis.
77
What is necrosis?
Uncontrolled cell death due to injury or disease.
78
What is the function of mitochondria?
They generate ATP through aerobic respiration.
79
What is the role of lysosomes?
They break down waste and cellular debris.
80
What is the function of peroxisomes?
They detoxify harmful substances and neutralize free radicals.
81
What is the cytoskeleton?
A network of fibers that provides structural support and facilitates cell movement.
82
What is the function of microtubules?
They help maintain cell shape and assist in intracellular transport.
83
What is the role of actin filaments?
They support cell shape and play a role in cell movement.
84
What are intermediate filaments?
Structural components that provide mechanical strength to cells.
85
What is the difference between kinetic and potential energy?
Kinetic energy is energy in motion, while potential energy is stored energy.
86
What is the first law of thermodynamics?
Energy cannot be created or destroyed, only converted from one form to another.
87
What is the second law of thermodynamics?
Energy conversions increase entropy (disorder) in a system.
88
What are anabolic reactions?
Reactions that build larger molecules from smaller ones, requiring energy.
89
What are catabolic reactions?
Reactions that break down large molecules into smaller ones, releasing energy.
90
What is oxidation?
The loss of electrons in a chemical reaction.
91
What is reduction?
The gain of electrons in a chemical reaction.
92
What is an oxidation-reduction (redox) reaction?
A reaction where one molecule is oxidized (loses electrons) and another is reduced (gains electrons).
93
What are hydrogen bonds, and why are they important?
Weak interactions between partially positive hydrogen and electronegative atoms; important for water properties and DNA structure.
94
What is the role of nitrogen in biological molecules?
It is a key component of amino acids, proteins, and nucleotides.
95
What is an amphipathic molecule?
A molecule that has both hydrophilic (water-attracting) and hydrophobic (water-repelling) properties, such as phospholipids.
96
How does pH affect enzyme activity?
Enzymes function within a specific pH range; extreme pH levels can denature enzymes.
97
What is the significance of the phosphate group in ATP?
The phosphate bonds store energy that is released when broken to power cellular processes.
98
What is a peptide bond?
A covalent bond that links amino acids together in proteins.
99
What is an allosteric site on an enzyme?
A site other than the active site where molecules can bind to regulate enzyme activity.
100
What is the role of cofactors in enzyme activity?
Cofactors are non-protein molecules that assist enzymes in catalysis, often metal ions.
101
What is competitive inhibition?
When a molecule competes with the substrate for binding to the enzyme’s active site, reducing enzyme activity.
102
What is non-competitive inhibition?
When a molecule binds to a site other than the active site, altering the enzyme's function.
103
How do phospholipids contribute to membrane structure?
They form a bilayer with hydrophobic tails inward and hydrophilic heads outward, creating a selective barrier.
104
What is the function of cholesterol in membranes?
It stabilizes membrane fluidity and integrity.
105
What is the function of transport proteins in membranes?
They help move substances across the membrane, either passively or actively.
106
What are glycoproteins?
Proteins with carbohydrate chains that play roles in cell recognition and signaling.
107
What is the sodium-potassium pump?
A membrane protein that actively transports sodium out and potassium into the cell, crucial for nerve signaling.
108
What is facilitated diffusion?
Passive transport of molecules across membranes via protein channels or carriers.
109
What is the difference between simple diffusion and facilitated diffusion?
Simple diffusion does not require a transport protein, whereas facilitated diffusion does.
110
What is secondary active transport?
The movement of substances against their gradient using energy indirectly from another transport process.
111
What is receptor-mediated endocytosis?
A specific type of endocytosis where cells ingest molecules via receptor binding.
112
What is autophagy?
The process by which cells digest and recycle damaged components.
113
What is the function of tight junctions in cells?
They create a seal between adjacent cells to prevent leakage of extracellular fluid.
114
What are gap junctions?
Channels that allow for direct communication between adjacent cells.
115
What is the function of desmosomes?
They anchor cells together, providing mechanical stability.
116
What is the function of peroxisomes?
Organelles that break down fatty acids and neutralize toxins.
117
What is a proteasome?
A protein complex that degrades damaged or unneeded proteins.
118
What is the role of ubiquitin in protein degradation?
Ubiquitin tags proteins for degradation by proteasomes.
119
What are microvilli?
Finger-like projections that increase surface area for absorption.
120
What is the function of centrioles?
Organizing microtubules for cell division.
121
What is the glycocalyx?
A carbohydrate-rich surface layer on cells that aids in recognition and protection.
122
What is the significance of the fluid mosaic model?
It describes the dynamic nature of membranes, where lipids and proteins move freely within the bilayer.
123
What is chemiosmosis?
The process by which ATP is generated using a proton gradient in mitochondria.
124
What is the law of conservation of mass?
Matter cannot be created or destroyed in a chemical reaction.
125
What are the major types of chemical bonds?
Ionic, covalent, and hydrogen bonds.
126
What is electronegativity?
The ability of an atom to attract electrons toward itself in a bond.
127
What is an endothermic reaction?
A chemical reaction that absorbs heat from its surroundings.
128
What is an exothermic reaction?
A chemical reaction that releases heat into its surroundings.
129
What is a solute?
A substance that is dissolved in a solvent.
130
What is a solvent?
A substance in which a solute dissolves to form a solution.
131
What is an amphipathic molecule?
A molecule that has both hydrophilic and hydrophobic regions.
132
What is an emulsion?
A mixture of two immiscible liquids, stabilized by an emulsifier.
133
What is molarity?
A measure of concentration, defined as moles of solute per liter of solution.
134
What is osmolarity?
The total concentration of solute particles in a solution.
135
What are hydrogen bonds?
Weak attractions between a hydrogen atom and an electronegative atom like oxygen or nitrogen.
136
What is a buffer?
A solution that resists changes in pH by neutralizing added acids or bases.
137
What is a zwitterion?
A molecule that has both positive and negative charges but is overall neutral.
138
What is a dipole?
A molecule with a positive and negative charge separation due to unequal electron sharing.
139
What are van der Waals forces?
Weak intermolecular forces that contribute to molecular interactions.
140
What is the importance of carbon in biological molecules?
Carbon forms the backbone of organic molecules due to its ability to form four covalent bonds.
141
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have no double bonds, while unsaturated fatty acids contain one or more double bonds.
142
What is the role of triglycerides?
They store energy in adipose tissue and provide insulation.
143
What is a phospholipid?
A lipid containing a phosphate group, forming the structural basis of cell membranes.
144
What is the function of steroid hormones?
They regulate metabolism, immune function, and development (e.g., cortisol, testosterone, estrogen).
145
What are amino acids?
The building blocks of proteins, consisting of an amino group, carboxyl group, and variable R group.
146
What is the primary structure of a protein?
The specific sequence of amino acids in a polypeptide chain.
147
What is the secondary structure of a protein?
Local folding patterns such as alpha helices and beta sheets stabilized by hydrogen bonds.
148
What is the tertiary structure of a protein?
The overall 3D shape of a protein due to interactions between R groups.
149
What is the quaternary structure of a protein?
The arrangement of multiple polypeptide subunits in a functional protein complex.
150
What is an enzyme?
A biological catalyst that speeds up chemical reactions by lowering activation energy.
151
What is the function of ATP?
ATP stores and transfers energy within cells for metabolic reactions.
152
What is the function of NADH and FADH2?
They carry electrons in cellular respiration to generate ATP.
153
What is glycolysis?
The breakdown of glucose into pyruvate, generating ATP and NADH.
154
What is the Krebs cycle?
A metabolic pathway that produces ATP, NADH, and FADH2 by oxidizing acetyl-CoA.
155
What is the electron transport chain?
A series of proteins in mitochondria that generate ATP using a proton gradient.
156
What is oxidative phosphorylation?
ATP synthesis powered by the movement of electrons through the electron transport chain.
157
What is the role of cytochromes in respiration?
They are proteins involved in electron transport and ATP production.
158
What is gluconeogenesis?
The production of glucose from non-carbohydrate sources like amino acids and glycerol.
159
What is glycogenesis?
The conversion of glucose to glycogen for storage in the liver and muscles.
160
What is glycogenolysis?
The breakdown of glycogen into glucose when energy is needed.
161
What is lipolysis?
The breakdown of triglycerides into fatty acids and glycerol for energy.
162
What is beta-oxidation?
The breakdown of fatty acids into acetyl-CoA for energy production.
163
What is transamination?
The transfer of an amino group from an amino acid to a keto acid, forming new amino acids.
164
What is deamination?
The removal of an amino group from an amino acid, producing ammonia and a keto acid.
165
What is urea formation?
The process of converting ammonia into urea for excretion in urine.
166
What is ketogenesis?
The production of ketone bodies from fatty acids during prolonged fasting or diabetes.
167
What is the function of chylomicrons?
They transport dietary lipids from the intestines to tissues.
168
What is the role of LDL and HDL?
LDL delivers cholesterol to tissues, while HDL removes excess cholesterol from blood vessels.
