Cell Chemistry and Biotechnology

Strand 4

Plant CellsCell wall*

Cell membrane

Cytoplasm

Large central vacuole*

Nucleus

Nuclear Envelope

Nucleuous

Mitochondria

Chloroplast*

Ribosomes

Smooth & Rough ER

Golgi Apparatus

Peroxisomes

Plasmodesmata

* organelles only found in plant cells

Only in PLANT cells:

Plants have cell walls.Plants have chloroplasts for photosynthesis.Plants have a large, central vacuole.

Only in ANIMAL cells:

Animal cells have centrioles.Animal cells have small vacuoles.

Differences?

Similarities? The following organelles are found in BOTH cells:

VacuolesNucleusCytoplasmCell MembraneMitochondrion

DNA, RNA and Protein Synthesis

DNADNA contains the instructions

for manufacturing proteins Instructions contain

information to make all cellular proteins

DNA is too important and therefore must stay in the nucleus (this is why we have RNA!)

RNAMessenger RNA (mRNA)

carries the genetic information copied from DNA

In the form of a series of three-base code “words,” each of which specifies a particular amino acid

Codons are translated into proteins at the Ribosome

Role of EnzymesWhat are enzymes?

Special proteins that speed up the chemical reactions of a cell to biologically useful rates

They lower the activation energy required for these reactions

Without enzymes, metabolism would neither progress through the necessary steps, nor would it be fast enough to serve the needs of the cell.

Enzymes are necessary for life!

VirusCan only reproduce using a ‘host’ or living cellsTakes over host cellDoes not have nucleiDon’t have cell membraneEach viral particle, or virion, consists of genetic

material, DNA or RNA, within a protective protein coat called a capsid

BacteriaHave cell wallsConsidered ‘living’Wide-range of shapes,

ranging from spheres to rods to spirals

One cell living organismReproduce independentlyProkaryotesNo nucleus

Transmission of DiseasesDirect Transmission: Direct exchange of

bodily fluids leading to disease

Ex: Touching an open wound

Indirect Transmission: Spread from person to person through a carrier

Breathing in a sneeze (air)

Drinking contaminated water (water)

Bitten by infected mosquito (animal)

Contaminated water is the leading cause of transmission in areas of poor sanitation and untreated sewage

Vaccination

Giving the body a weaker form of the pathogen allowing the person to build immunity to the disease

When encountering the actual disease they will get sick for a shorter period of time or not at all

Micro-organisms IN MY FOOD?!

● Bacteria○ Produce lactic acid during

fermentation■ Helps preserve foods■ Makes sour cream, buttermilk,

cheese and yogurt (dairy)● Yeast

○ Produces alcohol and air bubbles during fermentation

■ Helps bread rise■ Creates the alcoholic content in

some alcoholic beverages

BiotechnologyUtilizing biological processes for technology

Genetic Engineering

Changing an organism's DNA to produce different proteins

Transformation

Process where a cell takes in and expresses foreign material

Transduction

When bacteriophages (viruses that infect bacteria) are used to inject foreign DNA into a bacteria

Viruses are designed to have the DNA we want to put in the bacteria

Conjugation

Process where genetic material is passed between bacteria through cell-to-cell contact

Risks:Health risks

New allergens and toxinsExposure to toxic metals Other unknown effects

Creation of resistant organisms Antibiotic resistant bacteria

(super-bugs)Herbicide resistant weeds (super-

weeds)Pesticide resistant pests (super-

pests)

Ecosystem effectsBreeding/cross-pollination

between transgenic and non-modified organism can create a new unexpected species

Introduction of an invasive species disrupting an ecosystem

Benefits:Food production

More nutritious and plentiful Lower land useUsing less pesticides and

herbicides by making food that is less susceptible to pests

Longer shelf lifeStress resistant foodAble to make more food for a

cheaper price to help feed countries that are struggling

Ecosystem effectsHelp rehabilitate damaged or less-

fertile land Reduction of environmental

impact of food production and processing

Biofuel productionRenewable form of energy

Biotechnology