BSC 197 exam 1

Scientific Method

A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions.

Hypothesis

A testable prediction, often implied by a theory

Theory

Well-tested, comprehensive explanation

Eukarya

Plants, animals, fungi, protists

Bacteria

Eubacteria (e-coli and salmonella)

Archea

Ancient bacteria

Most important elements in life

Carbon, Oxygen, Hydrogen, and Nitrogen

Atomic Structure

Electron on outer shell, neutron and proton in center, nuclei.

Atomic Mass

Combined number of protons plus neutrons in nucleas

Atomic Number

The number of protons in the nucleus of an atom

Covalent Bonding

A bond formed when atoms share one or more pairs of electrons

Polar Covalent Bonds

Bonds in which electrons are not shared equally between atoms of different elements in a compound

Ionic Bonds

Formed when one or more electrons are transferred from one atom to another

Hydrogen Bonds

Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule

Polar molecules

Molecules that have an unequal distribution of charges

Monomer

Individual molecule that will be combined to make the large molecule

Polymer

The larger molecule made by combining monomers in a chain

Dimer

2 molecules held together with a covalent bond

Homopolymer

Polymer made up of same molecule

Heteropolymer

Polymer made up of different molecules

Hydrolysis

Splitting a covalent bond by attacking it with water

Glycosidic Linkage

Bond between monosaccharides

Monosaccharides

Single sugar molecules

Disaccharides

Formed by union of two monosaccharides by dehydration reaction

Polysaccharides

Many monomers in one polymer

Starches

Plants use for energy

Glycogen

Animals use for medium-term energy storage

Dehydration Reaction

A chemical reaction in which molecules combine by removing water

Carbohydrate Functions

Energy, storage, and structure

Cellulose

Carbohydrate component of plant cell walls.

Saturated Fats

Linear molecules, able to pack more tightly (solid at room temp)

Unsaturated Fats

Have angles and do not pack tightly (liquid at room temp)

Lipids

Nonpolar molecules that are hydrophobic

Nucleotides are comprised of

Pentose sugar, Nitrogen containing base, organic phosphate group

DNA sugar

Deoxyribose

RNA sugar

Ribose

Pyrimidines

Single ring (Cytosine, Thymine, and Uracil)

Purines

Double ring (Adenine and Guanine)

Phosphodiester Linkage

C3-O-P-O-C5

DNA bases

Adenine, Thymine, Guanine, Cytosine

RNA bases

Adenine, Uracil, Cytosine, Guanine

Adenine and Thymine

2 hydrogen bonds

Guanine and Cytosine

3 hydrogen bonds

Central Dogma of Molecular Biology

DNA-transcription-RNA-translation-protein

Amino End (N-Terminus)

Shows the first amino acid

Carboxyl End (C-Terminus)

Only end in unreactive carboxyl group

Primary Structure

Linear amino acid sequence

Secondary Structure

Protein folding or coiling (beta sheets, alpha helices)

Tertiary Structure

Interactions and bonds between amino acids and side chains to form proteins

Quaternary Structure

Multiple polypeptide chains form a larger protein

Denaturation

A process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive.

Energy input for plants

solar energy

Catabolism

Metabolic pathways that break down molecules, releasing energy.

Anabolism

Metabolic pathways that construct molecules, requiring energy.

Phosphorylate

Covalently linking a phosphate to another molecule

Enzymes

Proteins that speed up chemical reactions

Competitive Inhibition

Substance that resembles the normal substrate competes with the substrate for the active site

Noncompetitive Inhibition

inhibitor binds elsewhere on the enzyme; alters active site so that the substrate cannot bind

Amphipathic

Having both a hydrophilic region and a hydrophobic region

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water through a selectively permeable membrane

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

Active Transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Phagocytosis

"Cell eating"; an endocytic pathway by which a cell engulfs particles such as microbes or cellular debris.

Pinocytosis

"Cell drinking"; a type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

Receptor-Mediated Endocytosis

The uptake of specific molecules based on a cell's receptor proteins

Phagocytosis

Phagosome

Pinocytosis

Pinosome or uncoated vesicle

Endocytosis

Endocytic vesicle or coated vesicle

a mechanistic prediction based on previous observation

Which of the following best describes an hypothesis?

 a comprehensive explanation for how something works that has been well-supported by research

What do scientists mean when they use the word theory?

 covalent bond

What type of bond forms between atoms that are sharing one or more electrons?

 They are isotopes of the same element

You are looking at two atoms-Atom A has 6 protons 7 neutrons and 6 electrons; Atom B has 6 protons 6 neutrons and 6 electrons.  Which of the following statements is true regarding these atoms?

16

An atom has 8 protons, 8 neutrons, and 8 electrons-what is its atomic mass?

6

An atom has 6 protons, 7 neutrons, and 6 electrons.  What is the atomic number of this element?

 ionic bond

The type of bond that is formed by the attractive forces that result when one atom donates an electron to another atom is:

 hydrogen bond

What are the weak bonds that form between areas bearing weak positive and weak negative charges on polar covalent molecules called?

2

How many bonds will a oxygen atom make to mimic a full outer shell?

3

How many bonds will a nitrogen atom make to mimic a full outer shell?

 hydrogen bonds

The weak type of bonds that are formed between differently charged regions of two polar molecules are called:

 its polar nature

Many of the properties that make water useful in biological settings such as cohesion and adhesion are a direct result of which trait of water?

 hydroxyl group

Which functional group comprises only oxygen bound to hydrogen?

Carbon

Organic molecules are based on atoms of which element?

dehydration reaction

The specific type of reaction occurring while assembling a polymer that results in a water molecule being produced is called what?

 its three dimensional shape

What property of a molecule most determines its biological activity?

 Cellulose is a very straight molecule that can be packed together into bundles while angles in starch molecules prevent it from being tightly packed

Both cellulose and starch are polymers of glucose.  What property allows cellulose to be a durable molecules useful for structure, while starch is easily broken down and used for energy?

 C_xH_2xO_x

What is the general chemical composition of a simple sugar?

 3 fatty acid chains attached side-by-side to a common glycerol backbone

The general structure of a biological lipid can be described as:

 

lipids

Which of the four classes of macromolecules is not a true polymer and is nonpolar?

 variable R group

Which of the following is NOT part of a typical nucleotide?

 carbon 5

In a nucleotide, to which carbon in the pentose is the phosphate attached?

 phosphodiester linkages between carbon 3 and carbon 5

In a nucleic acid, nucleotides are connected by which specific type of bond?

 the first nucleotide added will always be at the 5' end

Nucleic acids have polarity, meaning that we can tell one end from the other.  Which of the following statements is true with respect to the polarity of nucleic acids?

 5' GATCGAAT 3'

Which of the following would be the correct complementary sequence to this strand of DNA: 5' ATTCGATC 3'  ? Note: remember the antiparallel structure of DNA, and that geneticists typically write single-stranded nucleic acid sequences in 5' to 3' orientations.

 peptide linkages between the carboxyl group of one amino acid and the amino group of another

Proteins are held together by what type of bonds?

cysteines

In tertiary structure of a single protein, which types of amino acids will interact to form a disulfide bridge

 secondary

Which level of protein structure is associated with localized folding events such as an alpha helix or beta pleated sheet?

primary

Which level of protein structure are you examining if you are looking at the sequence of amino acids from the amino terminus to the carboxyl terminus?

 amino acids with polar R groups

In tertiary structure of a single protein, which types of amino acids will interact to form hydrogen bonds?