• 1859 > — published On the

Origin of Species, introducing the theory of

natural selection to explain species diversity.

• developed the theory alongside

Alfred Russel Wallace, who reached

similar conclusions independently.

• Natural selection, often called “survival of

the fittest”

, suggests that individuals with

favorable traits are more likely to survive,

reproduce, and pass those traits on.

• Father of Biology

• Proposed the concept of “potential”

  inheritance; Thought inheritance was

  passed through blood

• Father of Taxonomy

  “organism organizer” (sabi ni sir prince)

• Developed the first scientific classification

  system in the 1700s.

• Father of Genetics

• Discovered fundamental laws of heredity.

  1865 > he published his investigations into

  the inheritance of pea plants.

• His work was not recognized during his

  lifetime but became crucial to biology after

  being rediscovered in the early 1900s.

Mendelian’s Law of Inheritance

1. Law of

2. Law of

3. Law of

• Founder of Cytogenetics

• German biologist and Anatomy Professor

• 1882 > he published the first illustrations of

human chromosomes.

• Introduced the term “mitosis”

• Discovered chromatin - a complex of DNA

and proteins.

• stain nucleus (aniline dye) and

found dark staining strands.

• 1879 > he led to the theory that cell nucleus

  is the bearer of the physical basis heredity.

• Cell division in plants

• Founder of the Germ Plasm Theory

• Germ Plasm - biological concept that states

  that heritable information is transmitted only

  by germ cells.

  • Genetic information is passed from

  generation to generation through

  these reproductive cells.

Sperm & Egg cells; 23 chromosomes

Body cells; 46 chromosomes (23 pairs)

• Co-founder of the Chromosome Theory

of Inheritance.

• 1902 > chromosomes were involved with

inheritance.

• First to hypothesize that chromosomal

abnormalities could cause cancer.

• Co-founder of the Chromosome Theory

  of Inheritance.

• 1903 > he proposed the Chromosome

  Theory of Inheritance, independently

  supported by Theodor Boveri— now known

  as the Boveri-Sutton Theory.

• He stated that the Mendelian laws

  of Inheritance could be applied to

  chromosomes.

• Combined the disciplines of cytology and

  genetics, coining the term “Cytogenetics”

• 1888 > he introduced the term

  “chromosome”

• Derived from the Greek words

  chroma (color) and soma (body)

REDISCOVERY OF MENDEL’S LAWS

1900 > they independently

rediscovered Mendel’s work while studying

plant hybrids.

1902 > he proposed that sex determination

was related to some special chromosomes.

• 1924 > he used the term “karyotype”

• Describe the complete set of chromosomes

in a cell, including their number, size, and

shape.

• Developed techniques for chromosome

preparation and visualization in plants.

Double helix shaped molecule

Contains all the genetic materials,

determines the information available for

building and maintaining an organism

Special structure that is found in cells.

Made up of an organized section/strand of

DNA that contains many genes.

Every human body cell has:

• 23 pairs = 46 chromosomes

• Specific characteristic of an organism.

• It can be determined by genes or the

environment or more commonly by

interactions between them.

• Special segment of DNA that is found on a

  chromosome. Codes for a particular protein

  that determines a particular trait, feature, or

  characteristic.

• Different forms of a gene, which produce

  variations in a genetically inherited trait.

  • Dominant allele

  • Recessive allele

• Specific location of a gene for some trait on

a chromosome.

• BRCA1 gene = breast cancer

○location: 17q21

○short arm: p arm (petit)

○long arm: q arm (queue)

• Allele that dominates over others in

  determining phenotype.

• Allele whose phenotypic expression is

  “hidden” when a dominant allele is present.

• Inheritance or biological inheritance.

• Individual who is heterozygous for a trait

  that only shows up in the phenotype of

  those who are homozygous recessive.

A pair of chromosomes that are similar in

length, gene position, centromere location.

Genes may contain different alleles.

• Observable expression of that genetic

information as cellular, morphological,

clinical, or biochemical trait.

• Physical

• What we see

• EXTERNAL

• Genetic makeup of an organism

• Determines phenotype

• INTERNAL

• When both alleles at a particular gene locus

  are the same.

• When the two alleles at a particular gene

  locus are different.

• German cell biologist

• 1889 - coined the term “nucleic acid”

• Replaced Miescher’s original term “nuclein”

• Renamed it after discovering that nuclein

exhibited acidic properties

• Swiss physiologist

• 1869 - isolated a new substance from the

  nuclei of white blood cells (WBC)

  • initially called it “nuclein”-

  • The nuclein exhibited acidic properties

• Three-subunit molecule in which a pentose

sugar is bonded to both a phosphate group

mand a nitrogen-containing heterocyclic

base

• Building blocks of Nucleic Acid

• Has Phosphate

• No Phosphate

• A two-subunit molecule in which a pentose sugar is

  bonded to a nitrogen containing heterocyclic base

Subunits

1. Sugar (Pentose)

2. Nitrogenous Base

3. Phospate

• Sugar unit of a nucleotide is either the

  pentose ribose (with oxygen) or the

  pentose 2’

• deoxyribose (no oxygen)

  2 prime (“) = at the second carbon

Subunits

1. Sugar (Pentose)

2. Nitrogenous Base

3. Phospate

• Derived from phosphoric acid

  Phosphate residue is attached to pentose

  sugar DNA/RNA via phosphodiester link

  Acidic, Nucleic acid

• All residues in the DNA/RNA carry a

  negative charge in physiologic pH

NITROGEN-CONTAINING

HETEROCYLIC BASES

A monocyclic base with six-membered ring

Cytosine, Uracil (RNA), Thymine (DNA)

NITROGEN-CONTAINING

HETEROCYLIC BASES

A bicyclic base with fused 5- and 6-membered rings

Adenine, Guanine - Pure silver (Ag)

RULE:

• is always attached to Carbon 1 of the sugar

RULE:

• a molecule of water is

  formed as the 2 molecules bond together

FORMATION:

bases, suffix -idine is used

(cytidine, thymidine, uridine)

FORMATION:

bases, the suffix -osine is used

(adenosine, guanosine)

FORMATION:

indicates that sugar unit is

deoxyribose (no oxygen)

TYPES OF NUCLEIC ACIDS AND

THEIR STRUCTURE

1. Deoxyribonucleic acid (DNA)

2. Ribonucleic acid (RNA)

• Nucleotide polymer in which each of the

monomers contains deoxyribose, a

phosphate group, and one of the

heterocyclic bases: adenine, cytosine,

guanine, and thymine

• Primarily located in the cell nucleus

• also found in small amounts within

mitochondria

• Primary function: storage and transfer

genetic information

TYPES OF NUCLEIC ACIDS AND

THEIR STRUCTURE

1. Deoxyribonucleic acid (DNA)

2. Ribonucleic acid (RNA)

• Ribose - sugar unit in the backbone of RNA

• Uracil instead of thymine pairs with adenine

• RNA molecules are smaller than DNA

  molecules

• Occurs in all parts of a cell

• Primary function: synthesis of proteins

1. Polynucleotide chains have sense of

directionality (antiparallel)

• 3’ unreacted hydroxyl group and

unreacted 5’ phosphate group

2. Polynucleotide have individuality

• nucleotide base sequence - basis

for the different amino acids

• The size of the interior of the DNA double

helix, limits the base pairs that can

hydrogen bond to one another

• Only pairs involving small base (pyrimidine)

and one large base (purine) correctly fit

• A-T ; G-C

• Apple Tree (Adenine + Thymine)

has 2 hydrogen bonds

• Group Chat (Guanine + Cytosine)

has 3 hydrogen bonds

• Combination of two single strands

• The Double Helix

• Sugar Phosphate

• Backbone: outside

• Bases: inside

• Bases form specific base pairs, held

together by complementary base

A DNA SHOULD BE/HAVE:

• Nature of two polynucleotide chains in DNA

double helix means that there is a 5’ (prime)

end and a 3’ (prime) end at both ends of the

double helix

A DNA SHOULD BE/HAVE:

• Pairs of bases in a nucleic acid structure

  that can hydrogen bond to each other

  • A-T ; G-C

TYPES OF RNA MOLECULES

• RNA formed by DNA transcription

• Post-transcription processing converts the

hnRNA to mRNA

TYPES OF RNA MOLECULES

RNA that carries instruction for protein

synthesis (genetic information) to the sites

for protein synthesis

TYPES OF RNA MOLECULES

RNA that combines with specific proteins to

form ribosomes, the physical site for protein

synthesis

TYPES OF RNA MOLECULES

RNA that delivers amino acids to the sites

for protein synthesis

TYPES OF RNA MOLECULES

RNA that facilitates the conversion of

heterogeneous nuclear RNA to the

messenger RNA

• Biochemical process by which DNA

molecules replicates

• Breaking of hydrogen bonds between

complementary bases

• Unwinding point of DNA which is constantly

  changing or moving

• At the origins of replication, DNA helicase

  unwinds the DNA double helix

• Untangle and reduce the tension of DNA strands

• Single Strand DNA Binding Protein

• Keep the strands separated by holding

  them in place, so that each strand can

  serve as a template for new DNA synthesis

synthesized

continuously in the

same direction

synthesized

discontinuously in short

fragments (okazaki)

Two strands of the DNA from unwinding

• Enzyme that synthesizes short RNA sequences

• FREE NUCLEOTIDES pair with their

  complementary base on template

  strands by means of hydrogen bonds

• Catalyzed the formation of a new phosphodiester

  linkage between the nucleotide and growing

  strand; joins the newly attached nucleotides

• create one continuous strand in the 5’

  -to-3’ direction

• Only one strand can grow continuously in

  the 5’-to-3’ direction

• The other strand is formed in short segment

  (Okazaki Fragments) in the 3’

  -to-5’

  direction

Joins segments together, acts as a glue

Breaks and gaps in okazaki fragments

ENZYMES IN DNA REPLICATION

• DNA Helicase

• Topoisomerase

• RNA Primase

• DNA Polymerase

• DNA Ligase

- exonuclease activity;

remove RNA primer & replaces

with DNA

ENZYMES IN DNA REPLICATION

• DNA Helicase

• Topoisomerase

• RNA Primase

• DNA Polymerase

• DNA Ligase

- repair function

ENZYMES IN DNA REPLICATION

• DNA Helicase

• Topoisomerase

• RNA Primase

• DNA Polymerase

• DNA Ligase

- main enzyme that

adds nucleotides in the 5’-3’direction

OTHER REQUIREMENTS IN DNA REPLICATION

DNA strand for hnRNA/mRNA synthesis

DNA strand for hnRNA/mRNA synthesis

Process by which the DNA direct the synthesis of

hnRNA/mRNA molecules that carry information

needed for protein synthesis

Non-template strand, gives the base sequence

present in the hnRNA except for U replacing T

POST TRANSCRIPTION:

• Conversion of hnRNA to mRNA

• Genes contains 2 segments:

Contains/codes for genetic information (DNA

segments that help express a genetic message)

POST TRANSCRIPTION:

• Conversion of hnRNA to mRNA

• Genes contains 2 segments:

Portions that do not convey genetic information

(DNA segments that interrupt a genetic message)

• Process of removing introns from hnRNA

molecule and joining the remaining exons

together to form a mRNA molecule

• Involves snRNA which always complexed

with snRNP

• Large assembly of snRNA molecules and proteins

involved in the conversion of hnRNA molecules to

mRNA molecules

• Process by which several different proteins that

are variations of a basic structural motif can be

produced from a single gene

• All of RNA molecules that can be generated from

• the genetic material in a genome

• Process by which mRNA codons are

  deciphered, and a particular protein

  molecule is synthesized

• Process by which the genetic message is

  decoded and used to make proteins

• Every cell contains 20 or more different

  tRNAs, each designed to carry a specific

  amino acid

Complex formed from a snRNA molecule and

several proteins

tRNA that has an amino acid covalently bonded to it

at its 3’ end through an ester linkage

Post translational modification

Gives the protein final form to be functional

1. An amino acid interacts with an activator

molecule to form a highly energetic complex

2. The complex reacts with tRNA to produce

an activated tRNA molecule

• The polypeptide chain continues to lenghten

until a stop codon appears on the mRNA

• The new protein is cleaved from last RNA

• 3 nucleotide sequence on a tRNA molecule

  that is complementary to a codon on a

  mRNA molecule

• 3 nucleotide sequence on a tRNA molecule

  that is complementary to a codon on a

  mRNA molecule

• Another tRNA with the second amino acid

  binds at the A site

• The methionine transfers from:

  • P site to A site

  • The ribosome shift to the next codon,

  making it a site available for the tRNA

  carrying the third amino acid

• mRNA attaches to the surface of a small ribosomal

  • subunit such that its first codon, which is always the

  initiating codon AUG-methionine, occupied the

  • DNA sequence

CHROMOSOME STURCTURES:

Found in the middle; Used during cell

division as attachment point

CHROMOSOME STURCTURES:

Two arms are nearly equal in length