Lesson 15 - Body Tissue II Flashcards
Biotechnology
Use of biological organisms for human purposes/practical tasks
The technical application of biological
knowledge for human purposes
Ex: cheese and win
Selective breeding of livestock and crops
Breakthroughs: Insulin and rice (enriching)
Recombinant DNA technology
Applied science that explores applications of cutting, splicing, and creating DNA
Recombined DNA
-DNA made in vitro from various DNA pieces
-Allows for DNA sequencing and gene manipulation
Take out the gene of human cell and move it somewhere else
Genetic engineering
Manipulation of the genetic makeup of cells or whole organisms
Restriction Enzymes
Cuts DNA molecule at specific DNA sequences (restriction sites)
-Can splice or copy DNA
Produces fragments with “sticky” ends
-can bond with sticky ends of other fragments
DNA ligase seals it all together
Plasmids
small circular pieces of DNA to which desired genes can be added and
inserted into bacteria for amplification
(make more)
DNA cloning
production of multiple copies of a specific gene or DNA segment
Mass production of protein or enzyme
Use of bacteria and plasmids
CRISPR - Gene editing
Clustered regularly interspace short palindromic (sequences) repeats
-immune response form bacteria
-Can remove defective segments or inter new gene segments (cut and pastes)
DNA microarrays
Testing for expression of many genes at once
DNA trays
Are you expressing the genes?
Electrophoresis
DNA can be separated based on size and charge
DNA is placed through a gel and electric is run through
Negative DNA moves toward the positive end
Smaller fragments move farther and faster
Copying DNA
Uses polymerase chain reaction, used to copy many chains of DNA
-this is a method called PCR
Makes millions of copies in a rapid process
Can be repeated 30-40 times
PCR (dna copying)
DNA sample:
DNA is heated to separate two
strands
Cooling - DNA polymerase (Taq)
is used to replicate the strands
* Bases / primers present
Repeats many times
Gene therapy
-Alteration of Gene
-Potential for treating disorders of a single defective gene
-uses various vectors for delivery of genes
(cut and replace faulty)
Has its issues:
-large scale production of human hormones
-production of safer vaccines
Trangenetics (transgenic)
DNA from one species is inserted into
another, bacteria or other animals
For gene manipulation and genetic
engineering
Genetic engineering
Is being used to improve agricultural productivity and food quality
Can insert genes for:
Larger plant size
Better flavour of plant
Better coats
Leaner meat
Faster maturation
combining the two: Genetic Engineering Creates Transgenic Organisms
Transgenic bacteria have been developed to produce the following:
Insulin
Human growth hormone
Erythropoietin
Tissue plasminogen activator (tPA)
Factor VIII (blood clotting factor needed by many
hemophiliacs)
Vaccines
Transgenic plants
Allows for choice of traits
Eg. Seedless
Thinner skin
Larger size
Resistance
Transgenic plants have been modified to express the following:
Increased resistance to freezing
Longer shelf life
Increased vitamin A
Edible vaccines
Human proteins (i.e., albumin)
Increased resistance to pests
Ex: golden rice (more vitamin A) and ventria rice (high protein, human genes)
Concerns: Decreased biodiversity
Health risks
Are the products safe for consumption?
Procedure safe?
Environmental risks
Economic exploitation of regional farmers
Transgenic animals
Contain genes from other organisms
- Injected desired gene into cell and incorporated
Bigger challenges:
-More difficult to introduce foreign DNA into animal cells
-Cloning more difficult
Eg. Bovine growth hormone
used to promote faster animal
growth
Engineered to be pharmaceutical “factories”
Human genes inserted into dairy animals and the desired human protein is then exported in the dairy
animal’s milk
Is gene therapy the future?
Gene therapy:
Introduction of human genes into human cells to treat or correct a disease
Obstacles:
Difficult to introduce genes into the “right” cells, where the genes would normally be expressed
Need effective means of delivering genes
Transgenic Therapy (Human)
Germ-line gene therapy
-Transgenic cells into stem cells
-Whole organism (new cells)
Somatic gene therapy
-Cells injected into tissue
-To correct disease
Eg. pancreas (existing cells)
Vectors Transfer Genes to Human
Cells
Retroviruses:
-Human genes packaged in retroviruses
and introduced into human cells
Problems with retroviral vectors:
* Will only insert genes into dividing cells
* Insertion sites are random
Liposomes
-phospholipid capsule with DNA
Injecting naked DNA
(all experimental)
Animal cloning
Totipotent cell: capable of generating a complete new organism
Cloning:
Using one or more somatic cells to make another genetically identical individual
Nuclear transplantation
The nucleus of an unfertilized egg cell
or zygote is replaced with the nucleus of a differentiated cell
-low working rate
-most animals live short lives and develop properly
Plants cloning
Great, easy cloners. Some differentiated cells are totipotent
Stem cells
-relatively unspecialized cell
-Can reproduces indefinitely
-Can differentiate into many types of specialized cells - given appropriate conditions
Types:
Totipotent
-Can become any cell
-Embryonic
Pluripotent
-Can become all types of
adult cells (not embryonic)
-Bone marrow
Multi-potent
-Can become many types of
cells
Uni-potent
Can become one type
E.g. skin
Cell differentiation
Different cell types result from different
gene expression in cells with the same DNA
-Differences in gene expression
-Not differences in the cells’ genomes
