Review 2 Flashcards
Nucleic acids
RNA or DNA
A macromolecule that is composed of repeating nucleotide units
Nucleotides
- form the repeating structural unit of nucleic acids
- composed of a sugar, one or more phosphates, and nitrogen-containing base
Double helix
helical structure formed when two strands of DNA (and sometimes RNA) bind to each other
folding and bending of double helix leads to three dimensional structure
Chromosomes
- structures within living cell that contain genetic material
- genes phsyically located within this structure
- contain very long segment of DNA (genetic material) and proteins(bound to DNA and give it structure)
Deoxyribose
sugar found in DNA
Ribose
sugar found in RNA
explain the connections of nucleotides
- bases are attached on the 1’ carbon atom of sugar, and phosphate groups are attached to the 5’ position
- 3’ OH groups allow covalent bonds between nucleotides
nucleoside
- structure in which a base is attached only to a sugar, with no phosphate attached to the sugar
Genome
all the genetic material that a cell, an organism, or a species can possess
gene
- a unit of heredity that may influence the outcome of a trait in anorganism
- at the molecular level, it is a segment of DNA that contains the info to make a functional product, either RNA or a polypeptide
traits
- observable characteristics of an organism
- specific properties of a character
- CONTROLLED BY genes and the environment
- morphological traits affect the appearance of an organism(red or white flowers)
- Physiological traits affect the ability of an organism to function(rate at which bacterium metabolizes sugar)
- behavioral traits are those that affect an organism’s behavior(bird mating call)
Four major, large cellular molecules
- nucleic acids, proteins, carbohydrates, and lipids
nucleic acids
- DNA or RNA, made of repeating nucleotide units
protein
a functional unit composed of one or more polypeptides
Carbohydrates
- organic molecules with the general formula Cn(H2O)n
- example: glucose
- large carbohydrates have multiple sugar units
Lipids
- general name for organic molecules that are insoluble in water
- found vastly in cell membranes
Examples of macromolecules
- proteins, carbohydrates, and lipids
(many repeating units/small building blocks for parts)
Describe how cellular structures come together from molecules and macromolecules
- nucleotides linked to become DNA, a macromolecule
- DNA in chromosomes, which also contain proteins to contribute to chromosome structure
- chromosomes in nucleus in eukaryotes, bounded by membrane of lipids and proteins
proteome
- the collection of all proteins that a given cell or species can make
Enzyme
a protein that functions to accelerate chemical reactions within the cell
polypeptide
- sequence of amino acids that is the product of mRNA translation
- one or more polypeptides fold and associate with each other to form a functional protein
Genetic code
- correspondence between a codon and the functional role that the codon plays during translation
- each codon specifies a particular amino acid or the end of translation
codon
- sequence of three nucleotides in mRNA that functions in translation
- start codon methionine initiates translation
- stop codons terminate translation
- other codons specify the amino acids within a polypeptide sequence according to the genetic code
Amino acids
- building block of polypeptides and proteins
- contains amino group, carboxyl group, and side chain
-sequence in polypeptides causes it to fold into particular structure; one or more of them forms a functional protein
Gene expression
- the process in which the info within a gene is accessed, first to synthesize RNA and usually polypeptides, and eventually to affect the phenotype of the organism
Transcription
syntehsizing RNA from a DNA template
mRNA
- messenger RNA
- a type of RNA that contains the info for the synthesis of a particular polypeptide
Translation
- synthesis of polypeptide using the information contained in the codons of an mRNA
Molecular level
- with regard to gene expression, the level of observation at which genes affect the molecular properties of an organism
(example is molecular process of transcription and translation lead to production of a particular protein)
Cellular level
- with regard to gene expression, the level of observation at which genes affect the traits of cells
(the function of proteins within a cell affects the structure and function of the cell)
organism level
the level of observation or experimentation that involves a whole organism
Population level
level of observation or experimentation that involves a population of organisms
(species maintain distinctive set of attributes in nature)
Alleles
an alternative form of a specific gene
Comparison of gene affect levels of pigmentation
- at the molecular level, pigmentation gene produces certain amount of pigment; slight differences in DNA sequences can lead to variation in function of the enzymes
- at the cellular level, the differences between the enzymes affect the amount of pigment produced
- at the organism level, the amount of pigmentation in the cells leads to the color on the wings
- at the population level, the differences between wing coloration variation are observed, with predation being a suspect of different coloration
Gene mutation
- relatively small heritable change that affects only a single gene
Norm of reaction
effects of environmental variation on a phenotype
