General Biology - Exam 1

What are the important characteristics of living things?

- Living things are organized (The hierarchical organization) - Living things require material and energy (They need to eat food that provide nutrients so they can have energy) - Living things maintain homeostasis - Living things respond (They interact with stimuli such as the environment and other organisms. Responding helps organisms survive.) - Living things reproduce and develop (They do this in order to maintain a population. Reproducing passes copies of an organism's genes to the new generation. Every living thing has DNA) - Living things have adaptations

Ions with a net negative charge

Anion

Two or more closely-related species make up a

Genus

Uncharged particles

Neutrons

A bond in which the sharing of electrons between atoms is fairly equal

Nonpolar covalent bond

Bond in which the sharing of electrons between atoms is fairly EQUAL

Nonpolar covalent bond

Polymer of nucleotides; both DNA and RNA are these

Nucleic acids

The ability of water molecules to cling to each other due to hydrogen bonding.

Cohesion

An atom is to a molecule as a population is to a

Community

Substance having two or more different elements in a fixed ratio

Compound

The chemical bond formed between two atoms when they share electrons in pairs, so that each atom provides half the electrons

Covalent Bond

Use sodium and chlorine to explain the formation of an ionic bond.

- Sodium has only one electron in its valence shell and tends to be an electron donor. Once it gives up this electron, the second shell, with its stable configuration of eight electrons, becomes its outer shell. - Chlorine tends to be an electron acceptor. Its valence shell has seven electrons, so if it acquires only one or more electron it has a stable outer shell. - When a sodium and chlorine atom come together, an electron is transferred from the sodium atom to the chlorine atom. Now both atoms have eight electrons in their outer shells.

Why do some atoms react with others while other atoms don't react at all?

- Stable number of electrons = NOT REACTIVE - All chemical reactions occur between the electrons of different atoms. When an atom has particular numbers of electrons around it, it is more stable - 2, 10, 18, etc. - The Noble Gases are examples of elements whose atoms don't react. They have a stable number of electrons and do not need to react with other atoms. - All other atoms have less stable electron numbers, so they react with each other and share electrons to be more stable. The most reactive elements tend to be short one or two electron or have one or two extra. For instance, fluorine (9) and chlorine (17) are short one electron from being the most stable and they are very reactive!

Triglycerides are described as being fats if they are solid at room temperature or oils if they are liquid at room temperature. What determines the difference?

- Unsaturated triglycerides are liquid at room temperature because they contain one or more double bonds between carbons and contain as many hydrogens as they can hold. - Saturated triglycerides are solid at room temperature and contain NO bonds between carbon atoms, which reduces the number of bonded hydrogen atoms.

What are the properties of water that help promote life?

- Water has a high heat capacity (The presence of many hydrogen bonds allow water to absorb a large amount of thermal energy without a great change in temperature. ) - Water has a high heat of evaporation (Hydrogen bonds must be broken to evaporate water.) - Water is a good solvent (This is because of its polarity. As a solvent, it dissolves a great number of substances, especially those that are also polar.) - Water molecules are cohesive and adhesive - Frozen water (ice) is LESS DENSE than liquid water (As liquid cools, the molecules come closer together)

How many different amino acids are there in nature?

20

What is unique about the hydrogen atom? What are the two ways that hydrogen atoms achieve stability?

A hydrogen atom has one proton and electron but no neutrons. In the atom, the outer shell is complete when it contains two electrons. If hydrogen is in the presence of a strong electron acceptor, it gives up its electron to become a hydrogen ion. This is known as covalent bonding.

What is the difference between a hypothesis and a theory?

A hypothesis is an uncertain belief that is established through reasoning while a theory is actually supported by various observations, experiments, and data.

What does the term polar indicate about a molecule?

A polar molecule is when one end of the molecule is slightly POSITIVE and the other is slightly NEGATIVE. Ex: A water molecule is a polar molecule

Modifications that make organisms better able to function in a particular environment. For example, penguins are birds but have special kinds of flippers to swim through water.

Adaptations

What does DNA contain?

Adenine, guanine, cytosine, and thymine (A, G, C, T)

What does RNA contain?

Adenine, guanine, cytosine, and uracil (A, G, C, U)

The ability of water molecules to cling to other polar surfaces.

Adhesion

Smallest particle of an element that displays the properties of the element

Atom

The level immediately below the molecule level in the organization of living things

Atom

What is the hierarchical organization of living things?

Atom --> Molecule --> Cell --> Tissues --> Organs --> Organ Systems --> Organisms --> Populations --> Communities --> Ecosystems --> Biosphere Each level is more complex than the one preceding it. As it increases, the level acquires new emergent properties.

Indicates the number of protons within the nucleus of an atom.

Atomic number

Indicates the average of atom mass units for all the isotopes of an atom.

Atomic weight/mass

Why is homeostasis important for all living things?

Basically, it is an essential process to keep living things alive and healthy. Homeostasis keeps the body's environment under control for cells to live and remain balanced while the organism is living in a constantly changing environment.

What are the monomers needed to form DNA and RNA?

Both DNA and RNA are nucleic acids, which are polymers of nucleotides.

Class of organic compounds that typically contain carbon, hydrogen, and oxygen in a 1:2:1 ratio; includes monosaccharides, disaccharides, and polysaccharides.

Carbohydrates

What are the major classes of organic molecules?

Carbohydrates, lipids, proteins, and nucleic acids

What elements are found in carbohydrates?

Carbon, hydrogen, and oxygen in a 1:2:1 ratio

What are the two functional groups on an amino acid that are used in joining two or more of them together?

Carboxyl and amino groups. Both groups are acidic. A peptide bond occurs when the carboxyl group of one amino acid joins the amino end of another.

A substance capable of initiating or speeding up a chemical reaction. (An enzyme is this)

Catalyst

Ions with a net positive charge.

Cation

Found in the cell walls of plants. They are formed together by glucose. They are the most abundant organic molecules on earth and animals cannot digest it.

Cellulose

A kind of polysaccharide that is found in paper and other indigestible substances. It is the main component of foods that are eaten to provide fiber.

Cellulose has been used to make paper as well as be a major source for plant fibers for cotton and hemp. Wood is about 42% of cellulose. And cellulose is insoluble in water.

Found in the cell walls of fungi and exoskeleton of some animals (Ex: a crab's shell contains this)

Chitin

What role does DNA play?

DNA contains genetic material that stores information for its own replication and for the sequence of amino acids in proteins,

Wrote "The Origin of Species" and developed the idea of natural selection to explain the evolution of organisms in the biosphere

Darwin

A chemical reaction in which subunits are joined together by the formation of a covalent bond and water is produced during the reaction. In essence, this reaction leads to something being built! This process is used to connect monomers together to make polymers.

Dehydration Synthesis

What process is occurring in polymer formation?

Dehydration synthesis

A sugar composed of two monosaccharides. It is formed when two sugars are joined together and a molecule of water is removed. For example, milk sugar (lactose) is made from glucose and galactose whereas cane sugar (sucrose) is made from glucose and fructose.

Disccharides

If an organism has a problem with metabolism, it may lead to a loss of homeostasis and an increase in

Disorder

Negatively charged

Electrons

Substance that cannot be broken down into substances with different properties; composed of only one type of atom

Element

A function or trait that appears as biological complexity increases.

Emergent Properties

Organic catalyst, usually a PROTEIN, that speeds a reaction in cells due to its particular shape

Enzyme

Even molecules with atoms that have covalent bonds can be polar. Glucose sugar can dissolve in water but something like methane can't. Glucose has carbon, hydrogen, and oxygen in it. Methane only has carbon and hydrogen. What element in glucose helps to make it polar?

Glucose dissolves in water because polar water molecules attach to the glucose molecules. The many hydroxyl (OH) groups it contains tend to increase the solubility of the molecule.

Provides energy storage in animals

Glycogen

The maintenance of normal internal conditions in a cell or an organism by means of self-regulating mechanisms Ex: - When you are hungry, your liver releases stored sugar to keep blood sugar levels within normal limits. - Body Temperature - Glucose concentration - Calcium levels - Fluid volume

Homeostasis

The weakest of the bonds; it is weaker than an ionic or covalent bond. Although just one kind of this bond is easily broken, several of these bonds are collectively quite strong.

Hydrogen Bond

A chemical reaction in which a water molecule is added to BREAK a covalent bond.

Hydrolysis

What process is occurring in the DIGESTION of polymers?

Hydrolysis

Type of molecule, often polar, that interacts with water by dissolving in water and/or by forming hydrogen bonds with water molecules

Hydrophilic

Type of molecule that is typically nonpolar and therefore does not interact easily with water

Hydrophobic

What are some atoms that commonly occur as anions?

Hydroxide anion, oxide anion, and sulfate anion

What are some specific examples of anions?

Hydroxide anion: OH-, oxide anion: O2-, and sulfate anion: SO42-

A supposition established by reasoning after consideration of available evidence; it can be tested by obtaining more data, often by experimentation.

Hypothesis

A charged particle that carries a negative or a positive charge

Ion

If an atom loses an electron, it becomes a ____ and has a _____ charge

Ion, +1

If an atom gains an electron, it becomes a ____ and has a _____ charge

Ion, -1

A chemical bond in which ions are attracted to one another by opposite charges.

Ionic bond

What is the strength of an ionic bond compared to other kinds of bonds?

Ionic bonds tend to be stronger than covalent bonds due to the columbic attraction between ions of opposite charges.

Molecules with the same molecular formula but a different structure, and therefore a different shape.

Isomers

Atoms of the same element having the same atomic number but a different mass number due to a variation in the number of neutrons.

Isotopes

What is the difference between an isotope and an ion?

Isotopes are the result of VARIATIONS in the number of NEUTRONS in the NUCLEUS of atoms of an element. Ions result from the LOSS or ADDITION of electrons to the OUTER LAYER of atoms.

The "Father of Taxonomy"; developed binomial nomenclature, the use of Latin names, and hierarchical classification

Linnaeus

Class of organic compounds that tend to be soluble in nonpolar solvents; includes fats and oils.

Lipids

The evolution of new species

Macroevolution

The evolution of taxonomic categories higher than the species level

Microevolution

A formula giving the NUMBER of atoms of each of the elements present in one molecule of a specific compound.

Molecular formula - Ex: Glucose's molecular formula is: C6H12O6

Union of two or more atoms of the same element; also, the smallest part of a compound that retains the properties of the compound.

Molecule

A small molecule that is a subunit of a polymer—e.g. glucose is this to starch

Monomer

Simple sugar; a carbohydrate that cannot be broken down by hydrolysis--e.g. glucose, also, any monomer of polysaccharides

Monosaacharides

Some carbohydrates are small and sweet-tasting while others are much larger molecules and are used for storage. Which of these fit monosaccharides or polysaccharides?

Monosaccharides are small and sweet tasting. Disaccharides contain two monosaccharides that have been joined during a dehydration reaction. while poly saccharides are long polymers of monosaccharides. Because of their larger structure, it is harder for the human tongue to sense the sweetness they contain.

An evolutionary process resulting from differences in the probability of survival among genetically different individuals in a population

Natural Selection

What is the main function of nucleic acids?

Nucleic acids' main function is to store information about how to copy or replicate itself but also specifics the order in which amino acids are to be joined to make a protein (DNA). It can also perform a wide range of functions within cells, which include protein synthesis and regulation of gene expression (RNA).

What are the steps in the Scientific Method?

Observation, form a hypothesis, conduct an experiment/making a prediction, gather data, accept/reject hypothesis, reach a conclusion

The observation that an atom is most stable when its outer shell is complete and contains eight electrons. - For any atom, the 1st electron shell can and wants to hold 2 electrons. All remaining shells (if present), can and want to hold 8 electrons.

Octet Rule

A molecule that ALWAYS contains carbon and hydrogen, and often oxygen as well; they are associated with living organisms

Organic Molecules

A covalent bond between amino acids which in turn make polypeptides that make up proteins.

Peptide bond

Found in the cell walls of bacteria

Peptidoglycan

Main series of reactions used in metabolism of plants; uses light to make glucose (sugar)

Photosynthesis

A bond in which the sharing of electrons between atoms is unequal.

Polar covalent bond

Bond in which the sharing of electrons between atoms is fairly UNEQUAL

Polar covalent bond

What is the bond that causes molecules like water to become polar?

Polar covalent bond

A macromolecule consisting of covalently bonded monomers; for example, a polypeptide is a ______ of monomers called amino acids.

Polymer

Polymer made from carbohydrate monomers; the polysaccharides starch and glycogen are polymers of glucose monomers

Polysaccharides

All photosynthetic organisms in a community

Producers

Polymer of amino acids; often consisting of one or more polypeptides, and having a complex three-dimensional shape.

Proteins

What organic molecules do contain nitrogen?

Proteins and nucleic acids

Which of the organic molecules are enzymes?

Proteins, enzymes are proteins composed of amino acids

Positively charged particles

Protons

What are the parts of an atom?

Protons, neutrons, electrons, and the nucleus

What role does RNA play?

RNA perform a wide range of functions within cells including: o Providing a temporary copy of a gene in DNA that specifies what the amino acid sequence will be during the process of protein synthesis (Messenger RNA) o Synthesizing proteins and helping translate the sequence of nucleic acids in a gene into the correct sequence of amino acids during protein synthesis. (Transfer RNA) o Working as an enzyme to form the peptide bonds between amino acids in a polypeptide. (Ribosomal RNA)

Contains NO double bonds between carbons. They tend to be SOLID at room temperature. (Ex: butter, lard)

Saturated fat

A standard series of steps used to gain new knowledge through research.

Scientific Method

What are some specific examples of cations?

Silver: Ag+, hydronium: H3O+, and ammonium NH4+

If you eat a bunch of starch and hold some in your mouth it may start to taste sweet. What is happening when this occurs?

Since starch is a carbohydrate, it is hydrophilic and goes through hydrolysis. Since your saliva is mostly water, it is breaking the covalent bonds of the starch by essentially adding a hydrogen cation to the starch. The starch is not soluble however, so all that is eventually left are the sugar-y nutrients left from the starch in your mouth.

Provides energy storage in plants

Starch

Which formula is most helpful in determining whether two or more molecules are isomers?

Structural Formula

A formula that shows the ARRANGEMENT of atoms in the molecule of a compound

Structural formula

The study of evolutionary relationships among different groups of organisms

Systematics

Give an example of a molecule made of atoms held together with POLAR covalent bonds.

The water molecule: in water, the oxygen atom is more electronegative than the hydrogen atoms; as a result, water molecules are polar. Moreover, because of its non symmetrical shape, the polar bonds cannot cancel each other, and water is a polar molecule.

A _____ is supported by a broad range of observations, experiments, and data.

Theory

How many other kinds of bonds are there?

There are single, double, and triple covalent bonds, all of which are fairly strong. However, the double and triple bonds are even stronger than the single.

What are proteins' main role?

They are of primary importance to the structure and function of cells. The following are some of the many functions of protein: metabolism, support, transport, defense, regulation, and motion.

What are lipid's main roles?

They are structural components. Their functions include long-term energy storage, heat retention, cell communication and regulation, and protection. They are insoluble in water due to their hydrocarbon chains.

What are carbohydrates' main role?

To provide the organism with energy and building material

If you eat a bunch of fat it is not necessarily a bad thing because it contains a lot of energy. What part of the fat molecule contains the energy?

Triglycerides

These are composed of glycerol and three fatty acids. Each fatty acid consists of either unsaturated or saturated fat.

Triglycerides

Contains one or more double bonds between carbons and contain as many hydrogens as they can hold. They are LIQUID at room temperature. (Ex: Plant oils)

Unsaturated fat

The outer electron shell of an atom. It contains the valence electrons, which determine the chemical reactivity of the atom. This is important because it determines many of an atom's chemical properties.

Valence Shell

What are some important carbohydrates?

Vegetables, whole fruit, legumes, potatoes and whole grains.

Which of the following is an abiotic component of an ecosystem?

Water