final exam Flashcards
What are the 7 key characteristics of life?
Grows Reproduces Responds to its environment Maintains homeostasis Evolves Has DNA Composed of cells
All life came from a single source (or a small number of sources)
Unity of Life
Organsims adapted to their environments over many generations
Diversity of Life
What are the hierarchal levels of life?
Atoms>molecules>organelles>cells>tissues>organs>organ systems>organsims
- All living things are made up of cells
- The cell is a structural and functional unit of all living things
- All cells come pre-existing cells
- Cells contain hereditary information which is passed from cell to cell during cell division
- All energy flow of life occurs within cells
- All cells are basically the same in chemical composition
Cell Theory
Has a nucleus, large cells or multicellular, DNA in strands
Eukaryotic Cells
No nucleus, small cells, circular DNA
Prokaryotic Cells
One organism
Individual
All the living organisms of one species in a particular area
Population
All species in an area (plants, animals, decomposers…)
Community
Living and non-living components of an area
Ecosystem
All life on Earth in all the places that life exists
Biosphere
New properties arise at each level of organization
Emergent Properties
The water molecules stick to each other, water has surface tension
Cohesion
Water sticks to certain other materials, wall of plant veins
Adhesion
Water loving
Hydrophilic
Water hating
Hydrophobic
What are the 4 main classes of organic molecules?
Carbohydrates, lipids, proteins, nucleic acids
What is the monomer of carbohydrates?
monosaccharide
What is the polymer(s) of carbohydrates?
Disaccharides (2), polysaccharides (3+)
What is the monomer of lipids
1 glycerol+3 fatty acids
What is the polymer of lipids?
Triglyceride
What is the monomer of proteins?
Amino acid
What is the polymer of proteins?
Peptides
What is the monomer of nucleic acids?
Nucleotide
What is the polymer of nucleic acids?
Nucleic Acid
Created by removing water and getting a larger polymer
Dehydration Synthesis
Break with water
Hydrolysis
The order of amino acids
Primary Structure
Stabilized by hydrogen bonds
Secondary Structure
The overall shape of a protein molecule
Tertiary Structure
Occurs in proteins formed of 2 or more peptide subunits
Quaternary Structure
The total amount of energy in the universe is constant
- Energy cannot be created or destroyed
- Energy can only be changed from one form to another
- Plants convert light energy to chemical energy via photosynthesis
First Law of Thermodynamics
The entropy (degree of disorder) is always increasing
- Energy is lost when it is transformed from one form to another
- Energy is generally lost as heat
Second Law of Thermodynamics
Releases energy, products low in potential energy
Exergonic Reactions
Absorbs energy, products rich in potential energy
Endergonic Reactions
What is the relationship between enzymes and activation energy?
Enzymes lower activation energy
What denatures an enzyme?
Changes in pH, temperature, and salt concentration
Is an enzyme used up during a reaction?
No
- Showed that killed pathogenic bacteria could transfer virulence to non-pathogenic bacteria
- This newly acquired trait of pathogenicity was inherited by all of the descendants of the transformed bacteria
Frederick Griffith
Identified the transforming substance as DNA
Avery, McCarty, MacLoed
Concluded that the DNA injected by the phage must be the molecule carrying the genetic information that makes the cells produce new viral DNA and proteins
-Provided powerful evidence that nucleic acids, rather than proteins, is the hereditary information
Hershey and Chase
Chargaff’s Rules, A=T, C=G
Erwin Chargaff
- Made an X-ray diffraction photograph of DNA which showed the helical structure
- Concluded that the sugar-phosphate backbone was on the outside
- Died in 1958
Rosalind Franklin
- Determined base pairing
- Determined the two strands of DNA were involved–double helix
- Determined the strands ran in opposite directions–antiparallel
Watson and Crick
Breaks hydrogen bonds between complementary pairs (unzips DNA)
Helicase
Adds a RNA primer to initiate replication
Primase
Adds DNA molecules to pre-existing chain from 5’ to 3’ on the growing chain
DNA Polymerase
Adds nucleotides after RNA primer
DNA Polymerase III
Removes RNA primer
DNA Polymerase I
Joins Okazaki fragments
DNA Ligase
Helps with the untwisting of DNA
Topoisomerase
Binds to the single strands to keep them from rejoining
Single Strand Binding Protein
The new complementary DNA strand synthesized continuously along the template strand
Leading Strand
A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments
Lagging Strand
Pries two strands of DNA apart and joins together RNA nucleotides complementary to the DNA template
RNA polymerase
DNA sequence where RNA polymerase attaches
Promoter
DNA sequence where RNA polymerase attaches
Terminator
What is produced from transcription?
mRNA
What is the ‘one gene-one enzyme’ hypothesis?
Each mutated gene must normally dictate the production of one enzyme
How does transcription vary in prokaryotes vs eukaryotes?
Prokaryotes produce mRNA, eukaryotes produce pre-mRNA
mRNA removed before transcription
Introns
Remaining mRNA to be used during translation
Exons
The process of remaining introns in the nucleus
RNA Splicing
Small nuclear ribonucleoproteins
- Composed of snRNA and proteins
- Recognize introns
snRNPs
A ribozyme, a catalyst that is a RNA molecule, not an enzyme
snRNA
Consists of snRNP subunits
-Bind to pre-mRNA at multiple sites along the intron, snip the intron, and join the exons
Spliceosome
Messenger RNA, carries the codon from the DNA to the ribosome
mRNA
Transfer RNA, brings amino acids to the ribosome
tRNA
Ribosomal RNA, components of ribosomes, most abundant RNA
rRNA
Structural components of spliceosomes which remove introns from eukaryotic pre-mRNAs
snRNA
Joins an amino acid to tRNA
Aminoacyl-tRNA synthetase
The messenger RNA nucleotide triplets
Codon
Base pairs with the complementary codon on the mRNA
Anticodon
Signals the start of translation
Start Codon
Signals the end of translation
Stop Codon
tRNA with the polypeptide moved to the p-site, empty tRNA moved to the e-site and released
Translocation
Contains a mRNA binding site
Small Subunit
Lines up the tRNA
Large Subunit