BIOL2170 Week 2
BIOL2170 Week 2 BIOL 2170 - 002
Popular in Fundamentals of Life Science: Biomolecules, Cells, and Inheritance
BIOL 2170 - 002
verified elite notetaker
Popular in Biology
This 5 page Class Notes was uploaded by Katie Veselka on Wednesday September 7, 2016. The Class Notes belongs to BIOL 2170 - 002 at University of Toledo taught by Robert M. Stevens in Summer 2016. Since its upload, it has received 29 views. For similar materials see Fundamentals of Life Science: Biomolecules, Cells, and Inheritance in Biology at University of Toledo.
Reviews for BIOL2170 Week 2
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/07/16
Lecture 3: Macromolecules II DNA 08/29/2016 A) Nucleic Acids a) DNA (deoxyribonucleic acid) I) Contains deoxyribose b) RNA (ribonucleic acid) I) Contains ribose II) More reactive then DNA c) Required for the storage and transmission of genetic information d) Polymers- the monomeric units are nucleotides I) Nucleotides consist of a pentose sugar, a phosphate group, and a nitrogen containing base B) Structure of DNA a) Molecular structures can be found through x-ray crystallography I) Crystals of a purified substance are generated II) Position of atoms is inferred by passing x-rays through the crystal and observing the diffraction patterns b) Chemical compositions also provide clues to the structure I) DNA is a polymer of nucleotides c) 1950: Erwin Chargaff found in the DNA from many different species I) Amount of A = amount of T II) Amount of G= amount of C III)Or, the abundance of purines= the abundance of pyrimidines d) The backbone of DNA and RNA consists of the sugars and phosphate groups, bonded by phosphodiester linkages I) The phosphate groups link the 3’ carbon in one sugar to the 5’ carbon in another sugar e) The two strands of DNA in the helix I) Run in opposite directions II) Are therefore antiparallel f) Hydrogen Bonds in DNA I) A and T are hydrogen bonded II) G and C are hydrogen bonded C) Key Features of DNA a) A double stranded helix I) All DNA molecules had the same structure (1) variation is in the sequence of base pairs b) Has a uniform diameter c) It is right-handed I) (helix orientation) d) It is antiparallel D) How do we know DNA is genetic material? a) 1920s: chromosomes consist of DNA and proteins b) Is DNA genetic material? I) It’s in the right place II) It is present in the right amount III)Amount varies among species c) Frederick Griffith I) Worked with two strains of a bacteria II) Determines that a chemical transforming principle, from dead cells of one strain produced a heritable change in the other strain. III)Oswald Avery- identifying the transforming principle IV) Treated samples to destroy different molecules V) Only if DNA was lost, was the transforming principle lost d) Hershey-Chase experiment I) Used the bacteriophage T2 virus to determine whether DNA or protein is the genetic material E) Genes in Eukaryotic Cells a) Next, genetic transformations of eukaryotic cells was demonstrated I) Called transfection b) Any cell can be transfected, even an egg cell I) Result is a transgenic organism F) Chemical Evolution a) Theory: Conditions of primitive earth led to the formation of large molecules unique to life I) Tested by Stanley Miller and Harold Urey in the 1950’s G) Catalyst: a) A substance that increases the rate of a chemical reaction without being permanently altered by the reaction b) Enzyme: catalyst produced by an organism c) Folded RNA molecules can act as catalysts I) Ribozymes II) RNA may have evolved first, at catalyzed its own replication as well as protein synthesis H) Spontaneous Generation a) Classic experiments disproved spontaneous generation I) Life appearing from inanimate matter b) Redi And Pasteur showed that life arises only from life Lecture 4: Transcription and RNA 08/31/2016 A) DNA Packaging a) DNA molecules are packaged so they can be more easily maintained in the cell I) Achieved by histones (1) Proteins with positive charges that attract negative phosphate groups of DNA II)Results in the formation if bead like nucleosomes IIITopoisomerase pack and unpack DNA B) How does the process work? a) Expression of a gene to form a polypeptide (two steps): I) Transcription: making a single stranded RNA copy of a gene II)Translation: using RNA sequence information to make a polypeptide b) Central dogma: information flows in one direction when genes are expressed I) Exceptions: (1) Viruses: non-cellular particles that reproduce inside cells, many have RNA as their genetic material C) RNA a) Usually one strand b) The sugar is ribose c) Contains uracil (U) instead of thymine (T) d) RNA can pair with a single strand of DNA, except that adenine pairs with uracil I) Single strand RNA can fold into complex shapes by internal base pairing e) Messenger RNA, mRNA forms a complimentary copy of DNA and carries information to the cytoplasm I) Made in the process of transcription D) Transcriptions a) Requires: I) DNA template II)Nucleotide substrates (ATP, GTP, CTP, UTP) IIIThe RNA polymerase enzyme catalyzes the synthesis of RNA b) Initiation requires a promoter—a special sequence of DNA in front of each gene I) RNA polymerase binds to the promoter II)Promoter tells RNA polymerase where to start and which strand of DNA to transcribe c) Polymerization of RNA occurs in a 5’ to 3’ direction I) Incoming ribonucleotides are accepted if they correctly base pair with the template DNA II)The 3’-OH of the growing strand attacks the high energy phosphate bond of the incoming ribonucleotides providing the energy to drive the reactions IIIThe two phosphates of the incoming ribonucleotides are released as pyrophosphate E) Eukaryotic cell organization a) Eukaryotic genes have noncoding sequences I) Introns b) Coding sequences are exons c) Introns and exons appear in the primary RNA transcript I) Pre-mRNA (1) Introns are removed from the final mRNA d) UTRs I) Untranslated regions are found at the 5’ and 3’ ends of mRNA transcripts (1) Important for the stability and transcription of the mRNA e) In the nucleus, pre-mRNA is modified at both ends I) G cap is added at the 5’ end (modified GTP) (1) Facilitates mRNA binding to ribosome f) Poly A tail added to the 3’ end I) AAUAAA sequence after the coding region is a signal for the enzyme to cut the pre-mRNA; then another enzyme adds 100 to 300 ATPs—the tail II)Adds stability to mRNA IIIMay assist in export form nucleus g) RNA splicing removes introns and splices exons together I) Consensus splice site sequences are found at the end of introns h) Alternative splicing: exons are not always spliced together in the same way; some may be selectively deleted F) Amino Acids a) Have carboxyl and amino groups I) They function as both acid and base b) The α carbon atom is asymmetrical I) Amino acids exist in two isomeric forms (1) D-amino acids (dextro, right) (2) L-amino acids (levo, left) c) Optical isomers result from asymmetrical carbons d) The side chains or R groups can have functional groups e) Amino acids are grouped based on the type of side chain f) Hydrophilic amino acids attract ions of opposite charges I) Tend to be on the outside of a cytoplasmic globular protein g) Polar hydrophilic amino acids form hydrogen bonds I) Also, see F,f,I h) Hydrophobic amino acids I) Tend to aggregate in the middle of a globular protein i) Know I) Cysteine II)Glycine III)Proline (1) Kinky due to odd structure
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'