The Chemistry of Life Flashcards
(176 cards)
1
Q
What is biology?
A
The scientific study of organisms, both living and after death, with the goal of discovering and understanding the underlying unity as well as the amazing diversity of complex processes that make up life.
2
Q
Define acids.
A
A substance that can release a proton in solution.
3
Q
What is adhesion?
A
The binding of one cell or substance to another.
4
Q
What is aerobic metabolism?
A
Occurring in the presence of oxygen; requiring or using oxygen.
5
Q
What is anaerobic metabolism?
A
Occurring without the use of molecular oxygen, O2.
6
Q
Define anions.
A
A negatively charged ion.
7
Q
What are atoms?
A
The smallest unit of a chemical element. Consists of a nucleus and one or more electrons.
8
Q
What are bases?
A
- A substance that can accept a hydrogen ion in solution. 2. In nucleic acids, the purine or pyrimidine attached to each sugar in the sugar–phosphate backbone.
9
Q
Define biomes.
A
A major division of the ecological communities of Earth, characterised primarily by distinctive vegetation and annual patterns of temperature and precipitation.
10
Q
What is the biosphere?
A
All regions of Earth and Earth’s atmosphere in which organisms can live.
11
Q
Define buffer.
A
A substance that can transiently accept or release hydrogen ions and thereby resist changes in pH.
12
Q
What are cations?
A
An ion with one or more positive charges.
13
Q
Define cells.
A
The simplest structural unit of a living organism. In multicellular organisms, many individual cells serve as the building blocks of tissues and organs.
14
Q
What is a chemical bond?
A
An attractive force stably linking two atoms.
15
Q
Define chemical reaction.
A
The change in the composition or distribution of atoms of a substance, with consequent alterations in properties.
16
Q
What is cohesion?
A
The tendency of molecules (or any substances) to stick together.
17
Q
What is a community in ecology?
A
A group of species living together at the same place and time.
18
Q
Define compound.
A
- A substance made up of atoms of more than one element. 2. Made up of many units, as in the compound eyes of arthropods.
19
Q
What is a covalent bond?
A
A chemical bond based on the sharing of electrons between two atoms.
20
Q
Define ecosystem.
A
The organisms of a particular community together with the physical and chemical environment in which they live.
21
Q
What is electronegativity?
A
The tendency of an atom to attract electrons when it occurs as part of a compound.
22
Q
What are electrons?
A
A subatomic particle outside the nucleus carrying a negative charge and very little mass.
23
Q
Define element.
A
A substance that cannot be converted to a simpler substance by ordinary chemical means.
24
Q
What is energy?
A
The capacity to do work or move matter against an opposing force.
25
What is Eukarya?
The formal taxonomic name for eukaryotes.
26
Define evolution.
The process by which living organisms change over time through changes in the genome.
27
What is evaporation?
The transition of water from the liquid to the gaseous phase.
28
Define homeostasis.
The maintenance of a steady state, such as a constant temperature, by means of physiological or behavioural feedback responses.
29
What is a hydrogen bond?
A weak electrostatic bond which arises from the attraction between the slight positive charge on a hydrogen atom and a slight negative charge on a nearby oxygen or nitrogen atom.
30
Define hydrophilic.
Having an affinity for water.
31
What is hydrophobic?
Having no affinity for water. Uncharged and non-polar groups of atoms are hydrophobic.
32
Define hydrophobic interaction.
A weak chemical interaction caused when molecules that are not attracted to water interact to exclude water.
33
What is an ionic bond?
An electrostatic attraction between positively and negatively charged ions.
34
Define isotopes.
Isotopes of a given chemical element have the same number of protons but differ in the number of neutrons.
35
What are liposomes?
A spherical structure contained by a membrane of phospholipids. Can be used to deliver drugs to cells.
36
Define mass.
A measure of the quantity of matter present.
37
What is a membrane?
A phospholipid bilayer forming a barrier that separates the internal contents of a cell from the nonbiological environment.
38
Define metabolism.
The sum total of the chemical reactions that occur in an organism.
39
What is a mole?
A quantity of a compound whose weight in grams is numerically equal to its molecular weight expressed in atomic mass units.
40
Define molecular weight.
The sum of the atomic weights of the atoms in a molecule.
41
What are neutrons?
One of the three fundamental particles of matter, with mass slightly larger than that of a proton and no electrical charge.
42
Define non-polar.
Having electric charges that are evenly balanced from one end to the other.
43
What are nucleic acids?
Compounds consisting of a nucleoside linked to a phosphate group.
44
What is the nucleus?
The centrally located compartment of eukaryotic cells that contains chromosomes.
45
Define organ systems.
An interrelated and integrated group of tissues and organs that work together in a physiological function.
46
What is an organism?
An individual animal, plant, or single-celled life form.
47
Define organs.
A body part composed of different tissues integrated to perform a distinct function.
48
What is oxidation?
The relative loss of electrons in a chemical reaction; often associated with the liberation of energy.
49
Define oxidation-reduction reaction.
A reaction in which one substance transfers one or more electrons to another substance.
50
What is pH?
The negative logarithm of the hydrogen ion concentration; a measure of the acidity of a solution.
51
Define phospholipid bilayer.
The basic structural unit of biological membranes; a sheet of phospholipids two molecules thick.
52
What is photosynthesis?
The metabolic processes carried out by green plants to synthesize compounds such as ATP and glucose.
53
Define polar.
Referring to a molecule with separate and opposite electric charges at two ends.
54
What is a product in a chemical reaction?
A molecule that results from the completion of a chemical reaction.
55
Define prokaryotes.
Unicellular organisms that do not have nuclei or other membrane-enclosed organelles.
56
What are proteins?
Large molecules composed of one or more long chains of amino acids and are essential for all living organisms.
57
Define protocells.
A self-organised sphere of lipids proposed as a stepping-stone to the origin of life.
58
What are protons?
A subatomic particle with a single positive charge; determines the element.
59
Define reactants.
A chemical substance that enters into a chemical reaction with another substance.
60
What is reduction?
The gain of electrons by a chemical reactant.
61
Define reversible reaction.
A chemical transformation that can occur in either direction.
62
What is a solute?
A substance that is dissolved in a liquid to form a solution.
63
Define solvent.
The liquid in which a substance (solute) is dissolved to form a solution.
64
What is a solution?
A liquid and its dissolved solutes.
65
Define specific heat.
The amount of energy that must be absorbed by a gram of a substance to raise its temperature by one degree centigrade.
66
What are tissues?
A group of similar cells organised into a functional unit.
67
Define van der Waals forces.
Weak attractions between atoms resulting from the interaction of the electrons of one atom with the nucleus of another.
68
What is DNA?
A nucleic acid molecule, usually a double-stranded helix, consisting of nucleotide monomers.
69
Define amino acid.
An organic molecule possessing both a carboxyl and an amino group; serves as the monomers of polypeptides.
70
What is a carbohydrate?
A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides).
71
Define disaccharide.
A double sugar, consisting of two monosaccharides joined by a glycosidic linkage formed by a dehydration reaction.
72
What is a disulphide bridge?
A strong covalent bond formed between two cysteine monomers.
73
Define fats.
A lipid consisting of three fatty acids linked to one glycerol molecule.
74
What is a fatty acid?
A carboxylic acid with a long carbon chain.
75
Define functional group.
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules.
76
What is a glycosidic bond?
A covalent bond formed between two monosaccharides by a dehydration reaction.
77
Define hydrolysis reaction.
A chemical reaction that breaks bonds between two molecules by the addition of water.
78
What is an isomer?
One of two or more compounds that have the same numbers of atoms but different structures.
79
Define lipids.
A group of large biological molecules, including fats, phospholipids, and steroids.
80
What is a macromolecule?
A giant molecule formed by the joining of smaller molecules.
81
Define monomer.
The subunit that serves as the building block of a polymer.
82
What is a monosaccharide?
The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides.
83
Define nucleic acid.
A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins.
84
What is a nucleotide?
The building block of a nucleic acid, consisting of a five-carbon sugar, a nitrogenous base, and one to three phosphate groups.
85
Define peptide bond.
The covalent bond between the carboxyl group on one amino acid and the amino group on another.
86
What is a polymer?
A long molecule consisting of many similar or identical monomers linked together.
87
Define polypeptide.
A polymer of many amino acids linked together by peptide bonds.
88
What is a polysaccharide?
A polymer of many monosaccharides, formed by dehydration reactions.
89
Define protein.
A biologically functional molecule consisting of one or more polypeptides folded into a specific structure.
90
What is a purine?
One of two types of nitrogenous bases found in nucleotides, characterized by a fused ring structure.
91
Define pyrimidine.
One of two types of nitrogenous bases in nucleotides, characterized by a six-membered ring.
92
What is RNA?
A type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers with ribose sugar.
93
Define saturated fatty acid.
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds.
94
What is translation?
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule.
95
Define unsaturated fatty acid.
A fatty acid that has one or more double bonds between carbons in the hydrocarbon tail.
96
What is a capsule in prokaryotes?
A dense and well-defined layer of polysaccharide or protein surrounding the cell wall.
97
Define cell membrane.
The membrane that surrounds the cell, regulating the entry and exit of molecules.
98
What is cell theory?
The theory that cells are the basic structural and physiological units of all living organisms.
99
Define cell wall.
A relatively rigid structure that encloses cells of plants, fungi, and most prokaryotes.
100
What is cytoplasm?
The contents of the cell, excluding the nucleus.
101
Define cytoskeleton.
The network of microtubules and microfilaments that gives a eukaryotic cell its shape.
102
What is cytosol?
The fluid portion of the cytoplasm, excluding organelles.
103
Define eukaryotes.
Organisms whose cells contain their genetic material inside a nucleus.
104
What are flagella?
A long, whiplike appendage that propels cells.
105
Define nucleoid.
The region that harbors the chromosomes of a prokaryotic cell.
106
What are organelles?
Any of the membrane-enclosed structures within a eukaryotic cell.
107
Define pili.
A structure that links prokaryote cells at the beginning of conjugation.
108
What are ribosomes?
Small particles in the cell that are the site of protein synthesis.
109
Define surface area to volume ratio.
The ratio of surface area to volume; important in setting an upper limit on the size of a cell or organism.
110
What are anchored membrane proteins?
Proteins that are associated with the membrane by covalent attachments to lipids.
111
Define cell junctions.
Specialized structures associated with the cell membranes of epithelial cells.
112
What is a ribosome?
A small particle in the cell that is the site of protein synthesis.
113
What does surface area to volume ratio refer to?
The ratio of surface area to volume; important for setting an upper limit on the size a cell or organism can attain.
114
What are cell junctions?
Specialized structures associated with the cell membranes of epithelial cells, contributing to cell adhesion and intercellular communication.
115
Define concentration gradient.
A difference in concentration of an ion or other chemical substance from one location to another, often across a membrane.
116
What is diffusion?
The random movement of molecules resulting in even distribution when no barriers are present.
117
What is endocytosis?
A process by which liquids or solid particles are taken up by a cell through invagination of the cell membrane.
118
What is facilitated diffusion?
Passive movement through a membrane involving a specific carrier protein; does not proceed against a concentration gradient.
119
What is the fluid mosaic model?
A molecular model for the structure of biological membranes consisting of a fluid phospholipid bilayer with proteins free to move.
120
Define glycolipid.
A lipid to which sugars are attached.
121
Define glycoprotein.
A protein to which sugars are attached.
122
What does hypertonic mean?
Having a higher solute concentration in comparison to another solution.
123
What does hypotonic mean?
Having a lower solute concentration in comparison to another solution.
124
What are integral membrane proteins?
Proteins that are at least partially embedded in the cell membrane.
125
What does isotonic mean?
Having the same solute concentration as another solution.
126
Define osmosis.
The movement of water across a differentially permeable membrane to a region with more negative water potential.
127
What is passive transport?
Diffusion across a membrane; may or may not require a channel or carrier protein.
128
What are peripheral membrane proteins?
Proteins associated with but not embedded within the cell membrane.
129
What is a phospholipid?
A lipid containing a phosphate group; an important constituent of cellular membranes.
130
What is pinocytosis?
Endocytosis by a cell of liquid containing dissolved substances within vesicles.
131
Define selective permeability.
The characteristic of membranes allowing certain substances to pass while excluding others.
132
What is a transmembrane protein?
An integral membrane protein that spans the phospholipid bilayer.
133
What is binary fission?
Reproduction of a prokaryote by division of a cell into two genetically identical progeny cells.
134
What is a cell cycle?
The stages through which a cell passes between one mitotic division and the next.
135
What are centrioles?
A paired organelle that helps organize microtubules during nuclear division.
136
Define centromere.
The region where sister chromatids join and microtubules attach to chromosomes.
137
What is chromatin?
The nucleic acid–protein complex that makes up eukaryotic chromosomes.
138
What is cytokinesis?
The process where the cytoplasm divides to form two new cells, each surrounded by a membrane.
139
What is DNA replication?
The process where the dividing cell’s genetic material must be duplicated for each new cell.
140
What is DNA segregation?
The distribution of replicated DNA to daughter cells, ensuring each receives a copy of every chromosome.
141
Define gamete.
The mature sexual reproductive cell: the egg or sperm.
142
What is a growth factor?
A chemical signal that stimulates cells to divide.
143
What is interphase?
The period between successive nuclear divisions when chromosomes are diffuse and the nuclear envelope is intact.
144
What are kinetochores?
Specialized structures on a centromere to which microtubules attach.
145
What is mitosis?
Nuclear division in eukaryotes leading to the formation of two daughter nuclei.
146
What is a nucleosome?
A portion of a eukaryotic chromosome consisting of DNA wrapped around histone molecules.
147
What is a somatic cell?
All the cells of the body that are not specialized for reproduction.
148
What is a spindle?
The array of microtubules emanating from both poles of a dividing cell during mitosis.
149
What is a capsule in prokaryotes?
A dense layer of polysaccharide or protein that surrounds the cell wall, protecting the cell.
150
What is a cell membrane?
The membrane that surrounds the cell, regulating the entry and exit of molecules.
151
What is a cell wall?
A rigid structure that encloses cells of plants, fungi, and many prokaryotes, giving shape and limiting expansion.
152
What are chloroplasts?
Organelles containing enzymes and pigments that perform photosynthesis, found only in eukaryotes.
153
What is a chromosome?
In eukaryotes, a structure composed of DNA and proteins bearing part of the genetic information.
154
What is collagen?
A fibrous protein found extensively in bone and connective tissue.
155
Define cytoplasm.
The contents of the cell, excluding the nucleus.
156
What is the cytoskeleton?
The network of microtubules and microfilaments that gives a eukaryotic cell its shape.
157
What is cytosol?
The fluid portion of the cytoplasm, excluding organelles and other solids.
158
What is the endomembrane system?
A system of intracellular membranes that exchange material with one another.
159
What is the endoplasmic reticulum?
A system of membranous tubes and flattened sacs found in the cytoplasm of eukaryotes.
160
What is endosymbiosis?
The theory that the eukaryotic cell evolved via the engulfing of one prokaryotic cell by another.
161
What are eukaryotes?
Organisms whose cells contain their genetic material inside a nucleus.
162
What is the extracellular matrix?
A material surrounding cells that performs many functions, including adhesion.
163
What are flagella?
Long, whiplike appendages that propel cells.
164
What is the Golgi apparatus?
A system of concentrically folded membranes found in eukaryotic cells, functioning in secretion.
165
What is an internal membrane?
A membrane enclosed within a membrane-bound organelle.
166
What are mitochondria?
Energy-generating organelles in eukaryotic cells.
167
What is a nuclear envelope?
A double membrane that encloses the cell nucleus.
168
What is a nucleolus?
A small body found within the nucleus of eukaryotic cells, the site of ribosomal RNA synthesis.
169
What are organelles?
Membrane-enclosed structures within a eukaryotic cell.
170
What is phagocytosis?
The process by which a cell engulfs a macromolecule or particle.
171
What are pili?
Structures that link prokaryote cells at the beginning of conjugation.
172
What are prokaryotes?
Unicellular organisms that do not have nuclei or membrane-enclosed organelles.
173
What are proteoglycans?
Glycoproteins containing a protein core with attached long carbohydrate chains.
174
What is a thylakoid?
A flattened sac within a chloroplast that contains chlorophyll.
175
What is a vacuole?
A membrane-enclosed organelle in plant cells for storage or turgor.
176
What is a vesicle?
A membrane-enclosed compartment within the cytoplasm associated with other organelles.
