ch4 ss

stopped on slide 19

A DNA molecule consists of two long __ ___ that contain ___ ___

polynucleotide chains
four subunits

What does antiparallel reading mean

One DNA strand is read from 5’ to 3’

Other is 3’ to 5’

What are the three parts of a nucleotide

deoxyribose (sugar)

phosphate group

base (ATGC)

The backbone of a nucleotide is formed by the

sugar and phosphate groups

How do sugar and phosphate groups form the backbone of a nucleotide

sugar of one bonds to phosphate of another covalently

The bonding of a sugar from a nucleotide to the next nucleotide’s phosphate group is known as a ___ Bond

phosphodiester

All four types of DNA nucleotides have the same sugar and phosphate, yet their ____ differs

base

A phosphodiester linkage connects the ___ position of a carbon to the ___ position of an adjacent sugar

3’ to 5’

How many hydrogen bonds form in A-T

2

How many hydrogen bonds form in G-C

3

Which bases are purines and how many rings do they have each

ag 2

which bases are primidines and how many rings do they have each

ct 1

What are major grooves

wide gap between two sugar-phosphate backbones

How do major and minor grooves function

allows proteins to recognize dna sequence without unzipping double helix

Where is most DNA located in a euk cell

Nucleus

The nuclear envelope is composed of an

inner / outer membrane

nuclear pores function in

regulation of transport between nucleus and cytosol

define + identify function

endoplasmic reticulum
rough:ribosomes attached, makes proteins “
smooth er:no ribosomes, makes lipids

Chromatin refers to

DNA and associated proteins

What aids in the folding and compacting of DNA

Protein

What does one unreplicated eukaryotic chromosome contain

single linear dna molecule + associated proteins

Besides packaging what processes do chromosome associated proteins help perform

gene expression
dna replication
dna repair

unreplicated vs replicated

unreplicated=before dna copy (I)
replicated after dna copy (x)