Nucleic Acids
Umbrella term used for DNA and RNA Macromolecules found in all living cells + essential
for life. Function = storage + expression of genetic info
The cell nucleus in interphase:
Functions
1. Genes - Determine characteristics of each individual cell
Contains info to make individual proteins
Incl enzymes = control most of cells activities
2. Provides info to cytoplasm + organelles to keep cell functioning properly
cells that have their nuclei removed
= metabolise for several days or weeks
cell starts to malfunction + unable to rejuvenate itself unless
another nucleus is put back into cytoplasm
Components of Nucleus:
1. Enclosed by nuclear membrane
consists of double membrane pierced by nuclear holes
pores control exchange of materials between nucleus and cytoplasm
2. Chromatin
diffuse form that chromosomes take when cell is not dividing
contains DNA (molecule of inheritance that controls activity of cell)
Diffuse state permits maximum surface with surrounding
nucleoplasm
= necessary in actively metabolising cells
When a cell is dividing: its chromosomes = visible
Analysis of chromatin reveals its made of 2 major components:
• Deoxyribonucleic acid (DNA) • Proteins
= DNA is molecule of hereditary within Called histones = stabilise DNA
whose structure is coded the info of molecules
inheritance + info for controlling the cell
3. 1+ Nucleoi = found in nucleus
Dark-staining, spherical structures
Synthesise ribosomes by producing ribosomal RNA (rRNA)
package it w/ ribosomal proteins to make ribosomes
,4. Nucleoplasm
contains ions + molecules necessary for construction of nucleic acids
manufactured in nucleus
Chromosomes
Each contains one long DNA molecules
when unraveled mould measure 4,8cm in length
Total length of DNA in nucleus of 1 single human cell = 22m
DNA = Intricately folded + tightly bond around histones
Most of cell cycle, DNA molecules are in long strands = Chromatin
Chromatin Chromosome
Composed of nucleosomes Condensed chromatin bres
Unpaired Paired
Thin, Long, Uncoiled structure Thick, compact, ribbon-like structure
Allows DNA replication No metabolic activity shown
Nucleic Acids
Molecules that originally thought to occur only in nucleus
2 Types
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)
Both are long, chain like structures — built up from repeating similar building blocks
= Polymers
any long chain of similar units joined end-end with each other
Each unit of a polymer = monomer ( building block )
In a nucleic acid, monomers are called nucleotides
Consists of 3 units bonded together:
1. Sugar Molecule
Deoxyribonucleic acid - sugar = deoxyribose
Ribonucleic acid - sugar = ribose
2. Phosphate group
3. Nitrogenous base
With each nucleotide
the nitrogenous base = joined to the sugar
the phosphate group = attached to the sugar
fi
, Deoxyribonucleic Acid (DNA)
DNA is a macromolecule / polymer that provides the template for making : cells proteins =
genetic code
most DNA in a eukaryotic cell is found in the nucleus
but also DNA in mitochondria and chloroplasts
How DNA carries the genetic code:
characteristics
1. Stores genetic information
2. Copy itself exactly — DNA replication
Each nucleotide in DNA can contain any 1 or the 4 nitrogenous bases
A = adenine
G = guanine
C = cytosine
T = thymine
Nitrogenous base is joined to deoxyribose sugar, phosphate group attached to
deoxyribose sugar
DNA molecules = very long
Humans have 23 Pairs of Chromosomes ( 70 000 genes )
OR
46 chromosomes
Broken down into smaller pieces of DNA = genes
make up coding DNA,
provides template for
making proteins
Each DNA molecule consists of 2 strands of nucleotides
bonded together in the middle by weak hydrogen bonds
between pairs of nitrogenous bases
Chemical Structure + shape of 2 bases in pair;
adenine only bonds with thymine (A — T)
guanine only bonds with cytosine (G — C)
Bases = complementary
Sides of double stranded structure are formed by alternating sugar-phosphate units
Base pairs from cross bridges
Each base pairing causes a slight twist in the structure
complete 360 turn every 10 base pairs
Molecule = double stranded helix
Umbrella term used for DNA and RNA Macromolecules found in all living cells + essential
for life. Function = storage + expression of genetic info
The cell nucleus in interphase:
Functions
1. Genes - Determine characteristics of each individual cell
Contains info to make individual proteins
Incl enzymes = control most of cells activities
2. Provides info to cytoplasm + organelles to keep cell functioning properly
cells that have their nuclei removed
= metabolise for several days or weeks
cell starts to malfunction + unable to rejuvenate itself unless
another nucleus is put back into cytoplasm
Components of Nucleus:
1. Enclosed by nuclear membrane
consists of double membrane pierced by nuclear holes
pores control exchange of materials between nucleus and cytoplasm
2. Chromatin
diffuse form that chromosomes take when cell is not dividing
contains DNA (molecule of inheritance that controls activity of cell)
Diffuse state permits maximum surface with surrounding
nucleoplasm
= necessary in actively metabolising cells
When a cell is dividing: its chromosomes = visible
Analysis of chromatin reveals its made of 2 major components:
• Deoxyribonucleic acid (DNA) • Proteins
= DNA is molecule of hereditary within Called histones = stabilise DNA
whose structure is coded the info of molecules
inheritance + info for controlling the cell
3. 1+ Nucleoi = found in nucleus
Dark-staining, spherical structures
Synthesise ribosomes by producing ribosomal RNA (rRNA)
package it w/ ribosomal proteins to make ribosomes
,4. Nucleoplasm
contains ions + molecules necessary for construction of nucleic acids
manufactured in nucleus
Chromosomes
Each contains one long DNA molecules
when unraveled mould measure 4,8cm in length
Total length of DNA in nucleus of 1 single human cell = 22m
DNA = Intricately folded + tightly bond around histones
Most of cell cycle, DNA molecules are in long strands = Chromatin
Chromatin Chromosome
Composed of nucleosomes Condensed chromatin bres
Unpaired Paired
Thin, Long, Uncoiled structure Thick, compact, ribbon-like structure
Allows DNA replication No metabolic activity shown
Nucleic Acids
Molecules that originally thought to occur only in nucleus
2 Types
1. Deoxyribonucleic acid (DNA)
2. Ribonucleic acid (RNA)
Both are long, chain like structures — built up from repeating similar building blocks
= Polymers
any long chain of similar units joined end-end with each other
Each unit of a polymer = monomer ( building block )
In a nucleic acid, monomers are called nucleotides
Consists of 3 units bonded together:
1. Sugar Molecule
Deoxyribonucleic acid - sugar = deoxyribose
Ribonucleic acid - sugar = ribose
2. Phosphate group
3. Nitrogenous base
With each nucleotide
the nitrogenous base = joined to the sugar
the phosphate group = attached to the sugar
fi
, Deoxyribonucleic Acid (DNA)
DNA is a macromolecule / polymer that provides the template for making : cells proteins =
genetic code
most DNA in a eukaryotic cell is found in the nucleus
but also DNA in mitochondria and chloroplasts
How DNA carries the genetic code:
characteristics
1. Stores genetic information
2. Copy itself exactly — DNA replication
Each nucleotide in DNA can contain any 1 or the 4 nitrogenous bases
A = adenine
G = guanine
C = cytosine
T = thymine
Nitrogenous base is joined to deoxyribose sugar, phosphate group attached to
deoxyribose sugar
DNA molecules = very long
Humans have 23 Pairs of Chromosomes ( 70 000 genes )
OR
46 chromosomes
Broken down into smaller pieces of DNA = genes
make up coding DNA,
provides template for
making proteins
Each DNA molecule consists of 2 strands of nucleotides
bonded together in the middle by weak hydrogen bonds
between pairs of nitrogenous bases
Chemical Structure + shape of 2 bases in pair;
adenine only bonds with thymine (A — T)
guanine only bonds with cytosine (G — C)
Bases = complementary
Sides of double stranded structure are formed by alternating sugar-phosphate units
Base pairs from cross bridges
Each base pairing causes a slight twist in the structure
complete 360 turn every 10 base pairs
Molecule = double stranded helix
