Exam 1

You isolate a molecule and determine it is nonpolar. Based on this property, the molecule is largely composed of the elements _____.

Carbon and hydrogen

The cell theory is one of the foundations of biology. Which of the following statements is not consistent with this theory?

Cells are found only in pairs, because single cells cannot exist independently

M: List and explain the key overarching themes of biology.

Cells, interaction between organisms, homeostasis, reproduction and genetics, evolution.

List the emergent properties of water that are important for biology, being able to describe the cause of each property and give examples of impacts on living organisms.

Cohesion- hydrogen bonds hold water molecules together High specific heat- Hydrogen bonds absorb heat when broken and release heat when formed High heat of vaporization- many hydrogen bonds must be broken for water to evaporate. Lower density of ice- water molecules are spaced out in ice because of hydrogen bonding Solubility- polar water molecules are attracted to ions and polar compounds = soluble.

Define covalent bonds

Covalent- highest relative strength. "Sharing" valence electrons by two atoms. Two elements who aren't very different.

M: Describe how DNA and RNA molecules store information.

DNA stores information in sequences of four bases of nucleic acids- adenine, guanine, thymine and cyostine. RNA stores in a type of code called quaternary code. The mRNA bases bind to the DNA bases temporarily, copying the DNA's code.

Name the two types of nucleic acids and describe how they differ in structure, monomer composition, and function. Describe how they store genetic information.

DNA- double helix where genetic information is stored and short lived copies are made in the form of RNA. RNA- stores information an dis in charge of protein synthesis.

Define isotope

Different forms of the element that have the same number of protons but a different number of neutrons.

M: For (DSC and PSC), List their primary functions in living organisms and the monomers that each are made of and the bonds that join the monomers.

Disaccharides- serve as transport molecules in plants and provide nutrition in animals Polysaccharides- provide energy storage and structural components.

Name and describe the most common disaccharides (DSC) and polysaccharides (PSC) found in nature.

Disaccharides- sucrose and maltose Polysaccharides- starch, glycogen, and cellulose.

Identify the basic structure that all amino acids share.

Each amino acid has the same fundamental structure , which consists of a central carbon atom, also known as the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom.

List the most common monosaccharides and their molecular formula

Glucose(C6H12O6) Fructose(C6H12O6) Galactose(C6H12O6)

Macromolecules are disassembled in ____________ reactions.

Hydrolysis

Which of the following is not involved in forming the native state of a tertiary protein?

Hydrophilic interactions

Which of the following functional groups is commonly found in all macromolecules?

Hydroxyl

Define atomic mass

The mass of an atom relative to other atoms.

Define atomic number

The number of protons plus the number of neutrons.

Discuss why protein structure is important. List and discuss the different levels of structure and what chemical mechanism(s) determine(s) each level of structure.

The shape of the protein determines function. Primary structure- amino acid sequence Secondary structure- hydrogen bonding backbone is alpha helix and beta sheet Tertiary structure- folds and links disulfide bonds covalent links Quaternary structure- subunit arrangements 2 or more polypeptide chains, nonequivalent

Define van der Waals bonding

Van der Waals- A weak force of attraction between electrically neutral molecules that collide with or pass very close to each other.

Define hydrogen bonds

a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.

If you change the number of neutrons in an atom, you create _____.

an isotope

Define ionic bonds

formed ions when "donating and taking" electrons. Any two ions in opposite charge can form an ionic bond.

What type of interaction is directly responsible for the formation of secondary structure?

hydrogen bonds between sections of the polypeptide backbone

M: Explain the nature of acids and bases, and their relationship to the pH scale.

pH scale is a more convenient way to express the hydrogen ion. concentration of a solution. (acid 1-6, neutral 7, base 8-14)

Which of the following is not a component of nucleic acids?

six-carbon sugar

Which of the following activities is not carried out by the endomembrane system?

Synthesis of ATP

Predict whether a given molecule will dissolve easily in water.

"like dissolves like" water molecules gather closely around any substance that bears an electrical charge. (full charge "ion" charge separation "polar molecule")

M: List five common misconceptions about evolution and explain what is wrong with each one.

- Evolution is a theory about the origin of life -Evolution only occurs slowly and gradually -Humans can't influence evolution -Genetic drift only occurs in small populations

List the different groups of amino acids and be able to place an amino acid into the appropriate group based on its R-group.

-non-polar and neutral -polar and neutral -acidic and polar -basic and polar.

List the three domains into which all living organisms are currently classified. Correctly place living organisms that you know of into the correct domain.

1. Bacteria- prokaryotic, unicellular 2. Archaea- prokaryotic, unicellular 3. Eukarya- eukaryotic, unicellular and multicellular

From its atomic number of 15, it is possible to predict that the phosphorus atom has _____.

15 protons and 15 electrons

Define element

A substance that cannot be decomposed into simpler substances by chemical means.

Define compound

A substance that consists of two or more elements in a unique composition.

What is the energy source of a cell?

ATP

Define biological evolution and explain two examples where it has been observed.

Any genetic change in a population that is inherited over several generations

Draw each of the common functional groups found in organic molecules and list the types of macromolecules that they are each found in.

Hydroxyl- found in carbs, proteins, nucleic acids and lipids Carbonyl- found in carbs and nucleic acids Carboxyl- found in proteins and lipids Amino- found in proteins and nucleic acids Sulfhydryl- found in proteins Phosphate- found in nucleic acids Methyl- found in proteins

Organic molecules that are used by organisms to store hereditary information are called

Nitrogenous bases molecules

The R groups of amino acids _____.

Non-polar=hydrophobic Polar=hydrophilic

Describe Darwin's theory of natural selection, including what it requires and how it works.

One of the basic mechanisms of evolution, mutation, migration, and genetic draft. It requires variation and the environment can't support unlimited population growth leading to extinction.

Define lipids, name the different types of lipids, and list the common uses of each in living organisms.

Perform three primary biological functions within the body: they serve as structural components of cell membranes, function as energy storehouses, and function as important signaling molecules. Triacylglycerols, phospholipids, and sterols.

Which one of the following is not a component of each monomer used to make proteins?

Phosphorus atom

Name and describe the reactions that are involved in the formation of polymers from monomers, as well as the formation of monomers from polymers.

Polymer to monomer- dehydration synthesis (take away water) Monomer to polymer- hydrolysis reactions (add water)

How are proteins constructed from monomers?

Proteins are linear polymers built of monomer units called amino acids.

List and describe the different monomers that make up nucleic acids, the three components they all contain, and the two different groups each base is placed into.

Purines- adenine (DNA and RNA) and thymine (DNA) Pyrimidines- cyostine (DNA and RNA) and guanine (DNA and RNA)