Download DNA AND BIOTECHNOLOGY

BIOTECHNOLOGY
and CANCER
CHAPTER 19 and CHAPTER 21
DNA AND
BIOTECHNOLOGY
DNA
A MACROMOLECULE THAT
CONTAINS THE INFORMATION
NEEDED TO BUILD PROTEINS
 AN ORGANISM’S STRUCTURE IS THE
RESULT OF ALL THE DIFFERENT
PROTEINS THAT ITS DIFFERENT
CELLS MAKE

GENE
A SEGMENT OF DNA THAT
CONTAINS THE RECIPE FOR A
PROTEIN
 A PROTEIN IS A POLYMER MADE OF
AMINO ACIDS CONNECTED
TOGETHER

CHROMOSOME
A LONG PIECE OF DNA
 CAN BE EXTENDED (CHROMATIN)
SO IT CAN BE READ
 CAN BE COMPACTED
(CHROMOSOME) SO IT CAN BE
EASILY MOVED AROUND WHEN THE
CELL DIVIDES

CHROMOSOMES
CHROMOSOMES ARE RECIPE
BOOKS MADE UP OF THOUSANDS
OF GENES (RECIPES FOR
PROTEINS)
 THE SUM OF ALL THE RECIPES IS
THE ORGANISM

DNA STRUCTURE
A POLYMER COMPOSED OF UNITS
CALLED NUCLEOTIDES
NUCLEOTIDE- PHOSPHATE, SUGAR,
BASE
DNA BASES= A, T, C, G

DNA structure
DNA CONT.
DNA IS A DOUBLE STRANDED HELIX
(SPIRAL)
 THE 2 STRANDS ARE HELD
TOGETHER BY HYDROGEN BONDS
BETWEEN COMPLEMENTARY BASES
 COMPLEMENTARY BASE PAIRING =
A-T AND G-C

DNA structure
REPLICATION
COPYING THE DNA BEFORE CELL
DIVISION
1. THE HELIX UNZIPS
2. DNA POLYMERASE INSERTS
COMPLEMENTARY NUCLEOTIDES
ACROSS FROM THE PARENT
STRAND
 WE HAVE 2 identical double stranded
DNA MOLECULES

DNA replication
RNA
ALSO A POLYMER MADE UP OF
NUCLEOTIDES
 DIFFERENT SUGAR, SINGLE
STRANDED
 U INSTEAD OF T, A-U AND G-C
 COMPLEMENTARY RNA COPIES ARE
MADE BY RNA POLYMERASE

RNA structure
3 TYPES OF RNA
rRNA- WILL BECOME PART OF
RIBOSOME
mRNA- A DISPOSABLE RNA COPY OF
A GENE
tRNA- TRANSFERS THE CORRECT
AMINO ACID TO THE RIBOSOME
WHERE IT WILL BE CONNECTED IN
THE CORRECT ORDER TO FORM A
PROTEIN
MAKING A PROTEIN
2 STEPS
1. MAKE AN RNA COPY (mRNA) OF THE
GENE FOR THE PROTEIN THE CELL
NEEDS= TRANSCRIPTION
2. THE RNA COPY GOES TO THE RIBOSOME
WHERE ITS INFORMATION IS USED TO
CONNECT THE CORRECT AMINO ACIDS
(AA’S) TOGETHER TO MAKE THE
PROTEIN= TRANSLATION

DNA CODE
IT TAKES A SET OF 3 BASES
(CODON) TO CODE FOR ONE Amino
Acid (PROTEIN INGREDIENT)
TRANSCRIPTION- MAKES A
COMPLEMENTARY RNA COPY OF A
GENE- RNA POLYMERASE
 TRANSCRIBE 30 BASES= ENOUGH
INFO FOR 10 INGREDIENTS (10 AA’S)

Transcription
TRANSLATION
THE mRNA MOVES TO THE
RIBOSOME WHERE IT IS READ AND
THE CORRECT PROTEIN IS MADE
 THE RIBOSOME ACTS AS THE
COUNTERTOP WHERE THE mRNA IS
READ AND THE CORRECT
INGREDIENTS (AA’S) ARE MIXED
(CONNECTED) TOGETHER

tRNA’s are gophers
EACH DIFFERENT tRNA HAS A 3
BASE ANTI-CODON SEQUENCE ON
ONE END
 THE OTHER END CARRIES A
SPECIFIC AMINO ACID
 WHEN THIS SEQUENCE IS
COMPLEMENTARY TO THE mRNA
CODON- THAT tRNA WILL RUSH IN
AND DROP OFF ITS AA

tRNA
AA’S

AS THE CORRECT AMINO ACIDS
ARE DROPPED OFF IN THE
CORRECT ORDER BY THE tRNA’S
(MATCHING THEIR ANTICODONS
WITH THE mRNA CODONS) THEY
ARE CONNECTED TOGETHER BY
PEPTIDE BONDS TO FORM A
POLYPEPTIDE= THE PROTEIN
Translation
Translation
Protein synthesis
BIOTECHNOLOGY
THE USE OF GENETIC ENGINEERING
TO PRODUCE A DESIRED PRODUCT
GENETIC ENGINEERING= THE
ALTERATION OF THE GENOME OF
VIRUSES, BACTERIA AND OTHER
CELLS

RESULTS

TODAY GENETICALLY ENGINEERED
ORGANISMS MAKE INSULIN,
GROWTH HORMONE AND MANY
OTHER DRUGS WHICH TREAT
CANCER AND CIRCULATORY
DISORDERS.
Genetic engineering
PRODUCING A PROTEIN
1. CUT THE GENE THAT CODES FOR
THE DESIRED PROTEIN OUT OF A
HUMAN CELL
2. SPLICE THE GENE INTO A VECTOR
WHICH TRANSFERS THE GENE TO
THE HOST CELL
3. THE HOST CELL WILL TRANSCRIBE
AND TRANSLATE THE GENE AND
GIVE US THE PROTEIN
FORENSICS
A SEQUENCE OF DNA IS PRECISELY CUT
OUT OF A HOST CELL WITH A
RESTRICTION ENZYME. IT IS THEN
COPIED HUNDREDS OF TIMES.
 USE ANOTHER RESTRICTION ENZYME TO
CHOP IT UP
GEL ELECTROPHORESIS- PROCESS THAT
SEPARATES THE CHOPPED UP
SEGMENTS BASED ON THEIR SIZES

FORENSICS
IDENTICLE DNA WILL FRAGMENT IN
THE SAME LOCATION WHICH WILL
PRODUCE THE SAME FRAGMENT
PATTERNS ON A GEL
 DNA FROM DIFFERENT PEOPLE
WILL FRAGMENT AT DIFFERENT
PLACES AND THE FRAGMENT
PATTERNS WILL BE DIFFERENT

TRANSGENIC ORGANISMS
BACTERIA- MAKE CHEMICALS AND
DRUGS (MAKE HUMAN INSULIN FOR
DIABETICS)
PLANTS- RESIST INSECTS, DISEASES
AND HERBICIDES, GROW BETTER
ANIMALS- BIGGER (PRODUCE
GROWTH HORMONE), PRODUCE
DRUGS IN THEIR MILK.
GENE THERAPY

GIVES GOOD GENES TO SOMEONE
WITH BAD GENES
Gene therapy
DNA PROBES



SMALL RADIOACTIVE SINGLE STRANDED
DNA SEQUENCES MIXED WITH
CHROMOSOME
CAN IDENTIFY THE LOCATION OF GENES
ON A CHROMOSOME BY HYBRIDIZING
(MATCHING) WITH THEM
USED TO IDENTIFY GENETIC DISEASES
CANCER
Causes of cancer
CAUSES
CARCINOGEN- THREE TYPES
RADIATION- X-RAYS, ULTRAVIOLET=
UV (SUN), RADON
ORGANIC CHEMICALS- TOBACCO,
HIGH FAT DIET, POLLUTANTS, DYES
VIRUSES- HEPATITIS B- LIVER
CANCER, GENITAL WARTSCERVICAL CANCER

HEREDITY
CERTAIN TYPES CAN BE INHERITED
AS MUTATIONS
 BREAST, LUNG AND COLON- IF A
FIRST DEGREE RELATIVE HAS IT
THEN YOUR RISK INCREASES 2-3x
 SOME LESSER KNOWN CANCERS
CAN BE INHERITED AS A DOMINANT
ALLELE

IMMUNODEFICIENCIES
OUR IMMUNE SYSTEM SOMETIMES
RECOGNIZES CANCER CELLS AS
“BAD” AND ATTACKS THEM.
 IF THE IMMUNE SYSTEM IS WEAK
(AIDS OR IMMUNOSUPPRESSIVE
DRUGS) THE BODY IS LESS LIKELY
TO ATTACK CERTAIN CANCERS.

CARCINOGENESIS
THE DEVELOPMENT OF CANCER
1. INITIATION- A MUTATION
2. PROMOTION- CELLS DIVIDE
QUICKLY
3. PROGRESSION- CANCER CELLS
INVADE BLOOD OR LYMPH VESSELS
AND SPREAD TO OTHER PARTS OF
THE BODY

Differences in cancer cells
CANCER CELLS UNDER THE
MICROSCOPE
NO DIFFERENTIATIONDISORGANIZED LAYERING,
GENERIC ROUND CELLS
ABNORMAL NUCLEI- ENLARGED
NUCLEUS, EXTRA OR MISSING
CHROMOSOMES
FORM TUMORS- CELLS KEEP
DIVIDING, A MASS OF CELLS IS
PRODUCED
TUMORS
BENIGN- TUMOR DOES NOT SPREAD,
ENCAPSULATED
MALIGNANT- TUMOR SHOWS SIGNS
OF SPREADING, HAS ITS OWN
BLOOD SUPPLY
ANGIOGENESIS
THE FORMATION OF NEW BLOOD
VESSELS TO SUPPLY A TUMOR
WITH OXYGEN AND NUTRIENTS
 CANCER CELLS RELEASE A
GROWTH FACTOR WHICH
PROMOTES THE GROWTH OF NEW
BLOOD VESSELS

METASTASIS
NEW TUMORS GROW IN LOCATIONS
AWAY FROM THE PRIMARY TUMOR
 CANCER CELLS MUST PRODUCE A
PROTEINASE ENZYME THAT EATS
THROUGH SURROUNDING TISSUE.
 WHEN A BLOOD OR LYMPH VESSEL
IS REACHED, CANCER CELLS ARE
CARRIED ELSEWHERE WITH THE
FLOW OF THESE FLUIDS

PROGNOSIS= LIKELY
OUTCOME
DEPENDS ON:
1. IF THE PRIMARY TUMOR HAS
INVADED SURROUNDING TISSUE
2. IF LYMPH NODES WERE INVADED
3. IF THERE ARE TUMORS IN OTHER
PARTS OF THE BODY

GENETIC BASIS
PROTO-ONCOGENES- NORMAL
GENES WHICH CODE FOR
PROTEINS WHICH REGULATE CELL
DIVISION
 A MUTATION CAN CHANGE THESE
GENES INTO ONCOGENES.
ONCOGENES- CAUSE CELL TO DIVIDE
REPEATEDLY
OTHER GENES
TUMOR SUPPRESSOR GENES- CODE
FOR REGULATORY PROTEINS THAT
ACT TO SLOW DOWN OR PREVENT
UNNECESSARY CELL DIVISION LIKE
A BRAKE
 IF THESE “BRAKES” ARE DAMAGED,
THEN CELL DIVISION MAY GET OUT
OF CONTROL
STATISTICAL CHANCES

1 OF EVERY 3 PEOPLE WILL
DEVELOP CANCER AND 1 OF EVERY
4 WILL DIE FROM IT.
DIAGNOSIS
SCREENING TESTS
 CERVICAL- PAP SMEAR- LOOKED AT
UNDER MICROSCOPE
 BREAST- SELF EXAM, MAMMOGRAM
 COLON- DIGITAL EXAM (FINGERS
FEEL FOR RECTAL CANCER),
SIGMOIDOSCOPY, STOOL BLOOD
TEST, BARIUM ENEMA / X-RAY.
SCREENING TESTS
LEUKEMIA- BLOOD TESTS
 BLADDER- URINALYSIS FOR BLOOD
OR CANCER CELLS

TUMOR MARKER TESTS



CANCER CELLS SOMETIMES PRODUCE
FOREIGN CHEMICALS THAT SHOW UP IN
BLOOD TESTS
MEASURING THESE CHEMICALS CAN
INDICATE THE PRESENCE OR
PROGRESSION OF CANCER (PROSTATE
CELLS MAKE PSA- OLDER MEN SHOULD
GET A PSA TEST)
HIGH PSA IN BLOOD MEANS OVERACTIVE
PROSTATE CELLS- COULD BE CANCER
GENETIC TESTS

LOOK AT DNA SEQUENCES OF
SPECIFIC GENES, USEFUL FOR
DETERMINING CANCER RISKS LONG
BEFORE A TUMOR DEVELOPS
OTHER TESTS
NEEDLE BIOPSIES DIRECTLY
SAMPLES LUMP AND THEN SENT
FOR MICROSCOPIC EXAMINATION
 CAT AND MRI SCANS
 ULTRASOUND

TREATMENT
SURGERY- REMOVES CANCEROUS
CELLS
RADIATION- KILLS CANCEROUS
CELLS (AS WELL AS SOME NORMAL
CELLS)
CHEMOTHERAPY- DRUGS THAT KILL
CANCER CELLS BY DAMAGING DNA
OR INTERFERING WITH WITH DNA
SYNTHESIS
CHEMOTHERAPY
SPECIFIC DRUGS ARE USED ON
SPECIFIC CANCERS
 DIFFERENT COMBINATIONS OF
DRUGS CAN BE USED TO AVOID
RESISTANCE PROBLEMS

ANTIHORMONE THERAPY
BLOCKS HORMONES THAT CAN
CAUSE CANCER
 ESTROGEN- CAN LEAD TO CANCER
OF BREAST
 TESTOSTERONE- CAN LEAD TO
CANCER OF PROSTATE

BONE MARROW TRANSPLANT
SOMETIMES USED TO TREAT BLOOD
CANCERS (Leukemia) BECAUSE BLOOD
CELLS ARE MADE BY BONE MARROW
1. REMOVE BONE MARROW AND THEN KILL
THE CANCEROUS CELLS IN IT
2. MASSIVE CHEMO AND RADIATION TO
KILL ALL CANCER CELLS IN THE BODY
3. REPLACE BONE MARROW

FUTURE TREATMENTS
IMMUNOTHERAPY- BREED TUMOR KILLING
WHITE BLOOD CELLS OR HOOK
CHEMOTHERAPY DRUGS TO ANTIBODIES
WHICH WILL ATTACH TO TUMOR CELLS
ANTI ANGIOGENESIS- DRUGS THAT CUT
OFF BLOOD SUPPLY TO TUMOR
ANTI METASTATIC- STOP ENZYME THAT
ENABLES SPREAD
GENE THERAPY- REPLACE ONCOGENES
WITH PROTO ONCOGENES