Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
This lecture covers the fundamental concepts of molecular biology, focusing on the roles of deoxyribonucleic acid (dna), ribonucleic acid (rna), and proteins in cellular function. Topics include the structure and composition of dna and rna, the processes of replication, transcription, and translation, and the importance of codons and amino acids in protein synthesis.
Typology: Study notes
1 / 28
CMSC 838T – Lecture 2
0 Gene sequences determine biological function 0 Genomic DNA → RNA → Proteins
0 Try to understand biological reasons for premise 0 Review of molecular biology 0 Describe useful experimental techniques
0 Lipid membranes (provide barrier) 0 Protein structures (do work) 0 DNA nucleus (store info)
CMSC 838T – Lecture 2
0 Sequence of nucleotides 0 Nucleotide = deoxyribose sugar + phosphate group + base
Base
CMSC 838T – Lecture 2
CMSC 838T – Lecture 2
Separating DNA into single strands
Forming double-stranded DNA
0 DNA can be represented as a sequence of letters (A,C,G,T) 0 5’ A T A C G T A 3’ 3’ T A T G C A T 5’ (matching strand, redundant)
0 Base pair (bp) – one pair of DNA bases (1 letter) 0 Gene – section of DNA that produces a functional product 0 Chromosome – physical linear sequence of DNA 0 Genome – entire collection of DNA for an organism O E Coli 1 chromosome 5 x 10 6 bases (5 Mbps) O Drosophila 8 chromosomes 2 x 10 8 bases (200 Mbps) O Human 48 chromosomes 3 x 10 9 bases (3 Gbps)
CMSC 838T – Lecture 2
0 Sequence of nucleotides 0 Nucleotide = ribose sugar + phosphate group + base 0 Single stranded (but may form hairpin loops) 0 Uracil (U) instead of Thymine (T)
0 RNA polymerase (enzyme)
CMSC 838T – Lecture 2
CMSC 838T – Lecture 2
0 Core + side chain (residue) 0 20 different residues → 20 unique amino acids A C D E F G H I K L M N P Q R S T V W Y
side chain (residue)
Amino acid
CMSC 838T – Lecture 2
Amino acid Symbol Codon
A Alanine Ala GC*
C Cysteine Cys UGU, UGC
D Aspartic Acid Asp GAU, GAC
E Glutamic Acid Glu GAA, GAG
F Phenylalanine Phe UUU, UUC
G Glycine Gly GG*
H Histidine His CAU, CAC
I Isoleucine Ile AUU, AUC, AUA
K Lysine Lys AAA, AAG
L Leucine Leu UUA, UUG, CU*
CMSC 838T – Lecture 2
0 ~40-500+ amino acids connected in polypeptide chain 0 Sequence determines 3D shape (and function) of protein
amino end
carboxyl end
side chains (residue)
Amino acid
Amino acid
forms peptide bond
Cα
R 2
N
H
C O
Cα
R 1
+ (^) H 3 N
C
O
N
H
Cα
R 3
C O
O - Φ ψ
0 Order of amino acid (residues) 0 Always begin at amino end (by convention) 0 Example (Hexokinase): A A S X D X S L V E V H X X V F I V …
amino end
residues
peptide bonds
carboxyl end
CMSC 838T – Lecture 2
X Alpha helix X Beta strand / pleated sheet X Coil
Alpha helix Beta strand
CMSC 838T – Lecture 2
CMSC 838T – Lecture 2
CMSC 838T – Lecture 2
0 Modifications during DNA replication
0 Point mutation / single nucleotide polymorphism ( SNP ) 5’ A T A C G T A … 5’ A T G C G T A … 0 Duplicate sequence 0 Inverted sequence 0 Insert / delete sequence ( indel )
CMSC 838T – Lecture 2