Test 1 objectives

Question 1

Distinguish between living and nonliving things by describing the features that characterize living organisms

Answer 1

• Every living organism is composed of one or more cells. Living things grow by increasing the size and/or number of their cells.
• Metabolism includes all the chemical activities that take place in the organism, including the chemical reactions essential to nutrition, growth and repair, and conversion of energy to usable forms. Homeostasis refers to the appropriate, balanced internal environment, and the organized tendency of the organism to maintain such a steady state.
• Organisms respond to stimuli, physical or chemical changes in their external or internal environment. Responses often involve movement.
• In asexual reproduction, offspring are typically identical to the single parent, except for size. In most plants and animals sexual reproduction involves the fusion of an egg and sperm. Genes are typically contributed by two parents, and there is variation in the offspring.
• As populations evolve, they become adapted to their environment. Adaptations are traits that increase an organism’s ability to survive in its environment.

Question 2

Construct a hierarchy of biological organization, including levels of an individual organism and ecological level (from the microscopic to the macroscopic!)

Answer 2

• Cells associate to form tissue.
• In most multicellular organisms tissues organize to form organs.
• An organized group of tissues and organs form an organ system.
• Functioning together, organ systems make up a complex, multicellular organism. •The basic unit of ecological organization is the population.
• Various populations form communities,
• A community and its physical, nonliving environment are an ecosystem
• All Earth’s ecosystems together make up the biosphere.

Question 3

What is meant by “structure is related to function”?

Answer 3

Everything adapts with certain function for survival. Neurons that function to transmit information is very different from the structure of red blood cells. With the same with canine teeth of carnivorous mammals are adapted for stabbing their prey and ripping flesh. Where herbivorous mammals have teeth adapted for cutting off bits of vegetation and grinding plant material.

Question 4

Summarize the importance of information transfer to living systems: between species & inside organisms

Answer 4

• Organisms transmit information chemically, electrically, and behaviorally.
• DNA, which makes up the genes, is the hereditary material. Information encoded in DNA is transmitted from one generation to the next. DNA contains the instructions for the development of an organism and for carrying out life processes. Among its many functions, DNA codes for proteins, which are important in determining the structure and function of cells and tissues.
• Hormones, chemical messengers that transmit messages from one part of an organism to another, are important in cell signaling.
• Many organisms use electrical signals to transmit information; most animals have nervous systems that transmit electrical impulses and release neurotransmitters.

Question 5

Discuss homeostasis, including negative and positive feedback mechanisms

Answer 5

• The term homeostasis also refers to the automatic tendency of the organism to maintain a steady state.
• In negative feedback, the accumulation of an end product of a process slows down or inhibits that process (e.g. pancreas releasing insulin after eating to maintain glucose levels back to a state of homeostasis).
• Less common, some biological processes are regulated by positive feedback, in which an end product speeds up its own production (e.g. the clotting of blood in response to injury)

Question 6

Demonstrate the binomial system of nomenclature by Carolus Linneaus and be able to use an example to classify domain, kingdom, phylum, class, order, family, genus, and species

Answer 6

• Did King Philip Come Over From Great Spain
• Millions of species have evolved. A species is a group of organisms with similar structure, function, and behavior that, in nature, breed only with one another. Members of a species contribute to a common gene pool and share a common ancestry.
• Biologists use a binomial system of nomenclature in which the name of each species includes a genus name and a specific epithet. Traditional taxonomic classification is hierarchical; it includes species, genus, family, order, class, phylum, kingdom, and domain. Each grouping is referred to as a taxon. A group of organisms with a common ancestor is a clade.

Question 7

Identify the six kingdoms of living organisms, and give examples of organisms assigned to each group.

Answer 7

• Bacteria and archaea are prokaryotes; all other organisms are eukaryotes. Prokaryotes make up two of the three domains.
• Organisms are classified in three domains: Archaea, Bacteria, and Eukarya and several kingdoms or clades: Archaea, Bacteria, Fungi (e.g., molds and yeasts), Plantae, and Animalia. Protists (e.g., algae, water molds, slime molds, and amoebas) are now assigned to several clades.

Question 8

Give a brief overview of the theory of evolution and explain why it is the principal unifying concept in biology

Answer 8

Evolution is the process by which populations of organisms change over time. The scientific theory of evolution has become the most important unifying concept of biology. Because of evolution we have the binomial systems for naming organisms, along with theories of gene pool and natural selection.

Question 9

Design an experiment to test a given hypothesis, using the procedure and terminology of the scientific method

Answer 9

• The process of science is a dynamic approach to investigation. The scientific method is a general framework that scientists use in their work; it includes observing, recognizing a problem or stating a critical question, developing a hypothesis, making a prediction that can be tested, making further observations, performing experiments, interpreting results, and drawing conclusions that support or falsify the hypothesis.
• Deductive reasoning and inductive reasoning are two categories of systematic thought used in the scientific method. Deductive reasoning proceeds from general principles to specific conclusions and helps us discover relationships among known facts. Inductive reasoning begins with specific observations and draws conclusions from them. Inductive reasoning helps us discover general principles.
• A hypothesis is a testable explanation for observations or phenomena. If no evidence is found to support it, the hypothesis is rejected. •A well-designed scientific experiment typically includes both a control group and an experimental group, and must be as free as possible from bias. The control group should be as closely matched to the experimental group as possible. Ideally, the experimental group differs from the control group only with respect to the variable being studied.
• A scientific theory is an integrated explanation of some aspect of the natural world that is based on a number of hypotheses, each supported by consistent results from many observations or experiments.

Question 10

Compare the physical properties (mass and charge) and locations of electrons, protons, and neutrons; distinguish between the atomic number and the mass number of an element. Be able to use the periodic table to determine the above items

Answer 10

• Each atom is composed of a nucleus containing positively charged protons and uncharged neutrons. Negatively charged electrons encircle the nucleus.
• An atom is identified as belonging to a particular element by its number of protons (atomic number). The atomic mass of an atom is equal to the sum of its protons and neutrons.
• A single proton or a single neutron each has a mass equivalent to one atomic mass unit (amu). The mass of a single electron is only about 1/1800 amu.

Question 11

What is an isotope?

Answer 11

An isotope is an element that has the same number of protons and electrons; only the number of neutrons varies.

Question 12

Define the term electron shell/level, and explain how the number of valence electrons of an atom is related to its chemical properties. Be able to draw an atom using our octet rule!

Answer 12

• In the space outside the nucleus, electrons move rapidly in electron orbitals. An electron shell consists of electrons in orbitals at the same principal energy level. Electrons in a shell distant from the nucleus have greater energy than those in a shell closer to the nucleus.
• The chemical properties of an atom are determined chiefly by the number and arrangement of its most energetic electrons, known as valence electrons. The valence shell of most atoms is full when it contains 8 electrons; that of hydrogen or helium is full when it contains 2. An atom tends to lose, gain, or share electrons to fill its valence shell.

Question 13

Describe and understand s & p orbitals.

Answer 13

• They are energy levels and sublevels of the electrons. Each energy level gets a s sublevel and has the electrons increases so does the energy level and the sublevels that hold the electrons in the valence shell.
• All s sublevels can only hold 2, while the p holds up to 6. The first energy level only holds 2. The second energy level holds 2 in the s and up to 3 in the s. The third is 2 in the s, and for this class we don’t go higher.
• The electron need to be placed in a certain order.

Question 14

Distinguish among covalent bonds, ionic bonds, and hydrogen bonds. Compare them in terms of the mechanisms by which they form and their relative bond strengths.

Answer 14

• Covalent bonds are strong, stable bonds formed when atoms share valence electrons, forming molecules. When covalent bonds are formed, the orbitals of the valence electrons may become rearranged in a process known as orbital hybridization. Nonpolar covalent bonds are formed if the electrons are shared equally between the two atoms. Polar covalent bonds are formed if one atom is more electronegative (has a greater affinity for electrons) than the other.
• An ionic bond is formed between a positively charged cation and a negatively charged anion. Ionic bonds are strong in the absence of water but relatively weak in aqueous solution.
• Hydrogen bonds are relatively weak bonds formed when a hydrogen atom with a partial positive charge is attracted to an atom (usually oxygen or nitrogen) with a partial negative charge already bonded to another molecule or in another part of the same molecule.
• van der Waals interactions are weak forces based on fluctuating electric charges.

Question 15

Understand the differences between atoms and ions and be able to determine proton and electron numbers for both. (example Na+ ion has how many protons? electrons?) What is a cation? An anion?

Answer 15

• An atom becomes an ion if it gains or looses 1 or more electron and has an electric charge.
• An atom with 1, 2, or 3 electrons in its valence shell tends to lose electrons to other atoms making it a positive charge cation.
• Atoms with 5, 6, or 7 electrons in its valence shell tend to gain electrons from other atoms and become negatively charged anions.

Question 16

Describe electronegativity (polar and nonpolar covalent)

Answer 16

• Electronegativity is a measure of an atom’s attraction for electrons in chemical bonds. Very electronegative atoms are “electron greedy.”
• When the electronegativity is similar between atoms, meaning the electrons are shared equally, the bond is described as a nonpolar covalent bond
• When there is an atom that is more electronagative then the other in the covalent bond it creates a polar covalent bond. Where the electrons are pulled more often to one side then the other causing a positive side and negative side (think Poles on earth in the N and S poles)

Question 17

Explain how hydrogen bonds between adjacent water molecules govern many of the properties of water-(for example polarity, cohesion, ect.)

Answer 17

• Water is a polar molecule because one end has a partial positive charge and the other has a partial negative charge. Because its molecules are polar, water is an excellent solvent for ionic or polar solutes.
• Water molecules exhibit the property of cohesion because they form hydrogen bonds with one another; they also exhibit adhesion through hydrogen bonding to substances with ionic or polar regions.
• Water has a high heat of vaporization. Hydrogen bonds must be broken for molecules to enter the vapor phase. These molecules carry a great deal of heat, which accounts for evaporative cooling.
• Because hydrogen bonds must be broken to raise its temperature, water has a high specific heat, which helps organisms maintain a relatively constant internal temperature; this property also helps keep the ocean and other large bodies of water at a constant temperature.
• The hydrogen bonds between water molecules in ice cause it to be less dense than liquid water. Because ice floats, the aquatic environment is less extreme than it would be if ice sank to the bottom.

Question 18

Describe patterns of chemical reactions. Be able to identify a synthes is reaction (and condensation reaction), a decomposition reaction (and hydrolysis) and an exchange reaction.

Answer 18

• Condensation reaction is a reaction in which two monomers are combined covalently through the removal of the equivalent of a water molecule; also called condensation synthesis. Compare with hydrolysis reaction.
• Hydrolysis is a reaction in which a covalent bond between two subunits is broken through the addition of the equivalent of a water molecule; a hydrogen atom is added to one subunit and a hydroxyl group to the other.

Question 19

In a chemical reaction, be able to identify products, reactants, and be able to balance equations!

Answer 19

• A chemical reaction is a process that involves rearrangement of the molecular or ionic structure of a substance.
• The reactants—the substances that participate in the reaction—are generally written on the left side.
• The products—the substances formed by the reaction—are written on the right side
• The arrow means “yields” and indicates the direction in which the reaction proceeds.
• To balance you would need to write out how many of each element is on each side of the equation. Then add lead coefiecents and re-add until each side is equal. Starting with everything but H and O and leaving these two for last.

Question 20

Be able to diagram the structural formula of a given molecule. Example: what is the structural formula of CH4? Hint: begin with Lewis structure, then fill in lines. Use atoms and molecules lab as a review.

Answer 20

• Structural formula is a type of chemical formula that shows the spatial arrangement of the atoms in a molecule.
• Example H-O-H represents H2O or water. Using the Lewis Dot structure would be drawing a dot for every valence electron the atom has and conecting the shared electrons (which is 2, one from each atom) with a line.

Question 21

How do you find molecular mass?

Answer 21

Also known as atomic mass, which is the total number of protons and neutrons in an atom; expressed in atomic mass units or daltons.

Question 22

Describe the properties of water-what makes it a good solvent?

Answer 22

• Water is a polar molecule because one end has a partial positive charge and the other has a partial negative charge. Because its molecules are polar, water is an excellent solvent for ionic or polar solutes.
• Water molecules exhibit the property of cohesion because they form hydrogen bonds with one another; they also exhibit adhesion through hydrogen bonding to substances with ionic or polar regions.

Question 23

Define hydrophilic and hydrophobic.

Answer 23

• Hydrophilic means to be able to interact readily with water; having a greater affinity for water molecules than they have for each other.
• Hydrophobic means to not be able to readily interacting with water; having less affinity for water molecules than they have for each other.

Question 24

Describe the pH scale and contrast acids and bases and discuss their properties. What does pH indicate?

Answer 24

• pH is the negative logarithm of the hydrogen ion concentration of a solution (expressed as moles per liter). Neutral pH is 7, values less than 7 are acidic, and those greater than 7 are basic.
• An acid is a proton donor.
• A base is defined as a proton acceptor.

Question 25

What is the function of a buffer and give example.

Answer 25

• A buffer is a substance in a solution that tends to lessen the change in hydrogen ion concentration (pH) that otherwise would be produced by adding an acid or base.
• For example, human blood contains a buffer called carbonic acid (H₂CO₃) and bicarbonate anion (HCO₃^-).

Question 26

Distinguish between organic and inorganic compounds.

Answer 26

• Organic compounds are compounds consisting of a backbone made up of carbon atoms.
• Inorganic compounds are simple substance that does not contain a carbon backbone.

Question 27

Describe the properties of carbon that make it the central component of organic compounds.

Answer 27

• Each carbon atom forms four covalent bonds with up to four other atoms; these bonds are single, double, or triple bonds. Carbon atoms form straight or branched chains, or join into rings. Carbon forms covalent bonds with a greater number of different elements than does any other type of atom.
• Some very simple carbon compounds are considered inorganic if the carbon is not bonded to another carbon or to hydrogen. carbon dioxide we exhale is an inorganic carbon compound.

Question 28

Define the term isomer and distinguish among the three principal isomer types.

Answer 28

• Isomers is one of two or more chemical compounds having the same chemical formula but different structural formulas (e.g., structural and geometrical isomers and enantiomers).
• Structural isomers is differing in the covalent arrangement of their atoms (e.g., glucose and fructose).
• Geometric isomers is differing in the spatial arrangement of their atoms or groups of atoms.
• Enantiomers is two isomeric chemical compounds that are mirror images.

Question 29

Identify and describe the functional groups present in organic compounds, and describe their properties.

Answer 29

• Hydrocarbons, organic compounds consisting of only carbon and hydrogen, are nonpolar and hydrophobic. The methyl group is a hydrocarbon group.
• Polar and ionic functional groups interact with one another and are hydrophilic. Partial charges on atoms at opposite ends of a bond are responsible for the polar property of a functional group.
• Hydroxyl (-OH) and carbonyl (-C=O) groups are polar.
• Carboxyl (-COOH)and phosphate (-PO₄H₂) groups are acidic, becoming negatively charged when they release hydrogen ions. The amino group (-NH₂) is basic, becoming positively charged when it accepts a hydrogen ion. •sulfhydryl group (-SH)

Question 30

Explain the relationship between monomers and polymers: What type of chemical reaction is associated with the bonding of monomers? of polymers?

Answer 30

• Long chains of monomers (similar organic compounds) linked through condensation reactions are called polymers. Large polymers such as polysaccharides, proteins, and DNA are referred to as macromolecules. They can be broken down by hydrolysis reactions.
• Monomers become covalently linked by condensation reactions
• Polymers can be degraded to their component monomers by hydrolysis reactions (“to break with water”).

Question 31

List the four major classes of organic compounds (and their characteristics) found in cells.

Answer 31

carbohydrates, lipids, proteins, and nucleic acids (DNA and RNA).

Question 32

What is the characteristic empirical formula of carbohydrates? Be able to identify a carbohydrate molecule.

Answer 32

• Formula 1:2:1 of CHO. example would be a simple glucose C6H12O6

Question 33

Distinguish among monosaccharides, disaccharides, and polysaccharides (characteristics & examples)

Answer 33

• Carbohydrates contain carbon, hydrogen, and oxygen in a ratio of approximately one carbon to two hydrogens to one oxygen. Monosaccharides are simple sugars such as glucose, fructose, and ribose. Two monosaccharides join by a glycosidic linkage to form a disaccharide such as maltose or sucrose.
• Most carbohydrates are polysaccharides, long chains of repeating units of a simple sugar. Carbohydrates are typically stored in plants as the polysaccharide starch and in animals as the polysaccharide glycogen. The cell walls of plants are composed mainly of the structural polysaccharide cellulose.

Question 34

How are lipids identified? Describe characteristics, and biological functions of each.

Answer 34

• Lipids are a heterogeneous group of compounds that are categorized by being soluble in nonpolar solvents (such as ether and chloroform) and relatively insoluble in water. Among the biologically important groups of lipids are fats, phospholipids, carotenoids (orange and yellow plant pigments), steroids, and waxes. Some lipids are used for energy storage, others serve as structural components of cell membranes, and some are important hormones.
• Lipids are composed mainly of hydrocarbon-containing regions, with few oxygen-containing (polar or ionic) functional groups. Lipids have a greasy or oily consistency and are relatively insoluble in water.
• Triacylglycerol, the main storage form of fat in organisms, consists of a molecule of glycerol combined with three fatty acids. Monoacylglycerols and diacylglycerols contain one and two fatty acids, respectively. A fatty acid can be either saturated with hydrogen or unsaturated.
• Phospholipids are structural components of cell membranes. A phospholipid consists of a glycerol molecule attached at one end to two fatty acids and at the other end to a phosphate group linked to an organic compound such as choline.
• Steroid molecules contain carbon atoms arranged in four attached rings. Cholesterol, bile salts, and certain hormones are important steroids.

Question 35

What is a saturated (and trans) versus unsaturated fatty acid? What are the basic components of a neutral fat?

Answer 35

A lipid that is an organic acid containing a long hydrocarbon chain, with no double bonds (saturated fatty acid), one double bond (monounsaturated fatty acid), or two or more double bonds (polyunsaturated fatty acid); components of triacylglycerols (neutral fat) is glycerol linked by ester linkage with 3 chains of fatty acids.

Question 36

Be able to identify steroid chemical structure & distinguish among the types of steroids.

Answer 36

Steroid molecules contain carbon atoms arranged in four attached rings. Cholesterol, bile salts, and certain hormones are important steroids.

Question 37

Give an overall description of the structure and functions of proteins.

Answer 37

• Proteins are complex macromolecules made of simpler subunits, called amino acids, joined by peptide bonds. Two amino acids combine to form a dipeptide. A longer chain of amino acids is a polypeptide. Proteins are the most versatile class of biological molecules, serving a variety of functions, such as enzymes, structural components, and cell regulators.
• Proteins are composed of various linear sequences of 20 different amino acids.

Question 38

What type of monomer is the basic unit of a protein?

Answer 38

Proteins, macromolecules composed of amino acids, are the most versatile cell components. Each type of protein consists of a unique set of amino acids linked in a chain that can be from several amino acids to hundreds of amino acids in length.

Question 39

Describe the features that are shared by all amino acids, and know the chemical structure of an amino acid (name the two functional groups associated with an amino acid)

Answer 39

An amino acid is an organic compound containing an amino group (—NH₂) and a carboxyl group (—COOH); may be joined by peptide bonds to form a polypeptide chain.

Question 40

What is an essential amino acid?

Answer 40

An amino acid that must be provided in the diet because the body cannot make it or cannot make it in sufficient quantities to meet nutritional needs.

Question 41

What type of bond links one amino acid to another?

Answer 41

Peptide bond - A distinctive covalent carbon-tonitrogen bond that links amino acids in peptides and proteins.

Question 42

Distinguish among the four levels of organization of protein molecules

Answer 42

• Primary structure is the linear sequence of amino acids in the polypeptide chain.
• Secondary structure is a regular conformation, such as an α-helix or a β-pleated sheet; it is due to hydrogen bonding between elements of the backbones of the amino acids.
• Tertiary structure is the overall shape of the polypeptide chains, as dictated by chemical properties and interactions of the side chains of specific amino acids. Hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges contribute to tertiary structure.
• Quaternary structure is determined by the association of two or more polypeptide chains.

Question 43

Describe the features that are shared by all amino acids, and know the chemical structure of an amino acid (name the two functional groups associated with an amino acid)

Answer 43

An amino acid is an organic compound containing two functional groups: an amino group (—NH₂) and a carboxyl group (—COOH); may be joined by peptide bonds to form a polypeptide chain.

Question 44

List the four nitrogenous bases found in DNA and RNA

Answer 44

Nitrogenous bases, aka purine or a single-ring pyrimidine. adenine (A) and guanine (G), the pyrimidines cytosine (C), thymine (T) and uracil (U)).

Question 45

Which nitrogenous base is only found in DNA? in RNA?

Answer 45

Purines in DNA is guanine (G) and adenine (A), the pyrimidines cytosine (C) and thymine (T). RNA contains the purines adenine (A) and guanine (G), and the pyrimidines cytosine (C) and uracil (U)

Question 46

What type of bond normally links two strands of DNA together?

Answer 46

Phosphodiester linkage or bond. Covalent linkage between two nucleotides in a strand of DNA or RNA; includes a phosphate group bonded to the sugars of two adjacent nucleotides.