Microbial Systems L.N1

Lecture N.1

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What is the cell?

fundamental building block of life

Critical ways how the cell can be distinguished

Growth and reproduction (self-produce), organized and selective , major elements, self-feeding .

Classification of the cells

Prokaryotes (don't have a nucleus) and Eukaryotes (true nucleus)

What are the viruses?

They aren’t real cells, they depend on a host for replication.

What is a prion?

Totally protein

What can abnormal prions do?

They are infectious and can destroy the brain tissue and It can look like a spongy appearance

All bacteria are microbes but not all microbes are bacteria. True or false?

True

For what is the morphologies cell in prokaryotic cell?

They are helpful to characterize cells, filamentous bacteria are dangerous

What is the cell structure in BACTERIAL cells?

Cell wall, cytoplasmatic membrane, nucleoid, cytoplasm, plasmid, ribosomes.

Explain each one

• Cell wall: rigidity and protects the membrane (in bacterias they are made of 2 sugars)

• Cell membrane: Barriers to influx the nutrient, create a separate environment (Function: transport, support for proteins, outside and inside reactions)

• Ribosomes : They are in euk. and prok. , protein synthesizing, prok. only have one free ribosome, 60% rRNA, 40% protein 20nmm in diameter

• Nucleoid: Closed circular DNA

• Plasmid: Circular, double stranded DNA molecules and replicate independently

What are special membranes in bacterial cells?

Extreme environment, special type of lipid and its called “archaebacteria”

What is the cell structure in EUKARYOTES cells?

Cell wall, cytoplasmatic membrane, mitochondrion, nuclear membrane, nucleus, ribosomes, endoplasmatic reticulum, cytoplasm, Golgi complex

Explain each one

• Cell wall: (fungi, plants,animals)

• Membrane: basic features (plasma membrane and cytoplasm)

• Ribosomes: Protein synthesizing , rRNA protein radio 1:1 , 25-30 nm in diameter

• Endoplasmatic reticulum: only in euk. site of protein synthesis

• Mitochondrion: unique strcutres of fungi, plants, animals, ONLY IN EUKARYOTES energy production

• Golgi: proteins inside before they are sent, importan in the process of proteins

• Nucleus: only in euk., linear DNA with chromosomes

• Chloroplasts: organelles made conversion of light to energy

why in the chloroplasts the lost of internal membranes?

because It needs a specific surface area to the activity occurs

What does the mitochondria do?

Produce of chemical energy and is stored in ATP (adenosine triphosphate)

Binary fission of prokaryotes

cell numbers and components double every generation

for what is mitosis ?

cell division for growth, cellular reproduction and repair of the body

For what is meiosis?

sexual reproduction, produces sex cells

Covalent bonds and examples

Macromolecules from small organic molecules (Proteins ←amino acids)

Noncovalent bonds

Determine the shape and stabilize complexes of two or more molecules

Types of non covalent bonds

• Hydrogen bonds - complementary DNA

• Ionic bondes - ion-protein

• Van der waals - protein-protein

• Hydrophobic interactions - protein-folding

Which is the most strong chemical bond formed by sharing a pair of electrons?

Covalent bond, one single bond is 80kcal

What is a Hydrogen bonds?

noncovalent bond, interaction of a hydrogen atom with an electronegative atom such as oxygen

Hydrogen bonds has solubility decreases sharply with chain length, why? (solubilidad disminuye bruscamente con la longitud de la cadena)

It’s difficult to form organized other arregment, entropy is lower, is more organized and entropy represents caos

Chemical macromolecular characteristics of prokaryotic cells

• proteins (50-60%)

• carbohydrates (10-15%)

• lipids (6-8%)

• nucleic acids (DNA - 3% , RNA 15-20%)

Mention the four main families of small organic molecules in cells

• Fatty acids → lipids → essential of membranes, energy storage molecules

• Sugars → carbohydrates → energy storage and production

• Aminoacids → proteins → they’re in everywhere, machines for different process

• Nucleotides → Nucleic acids → storing genetic code

Difference between Hydrophilic and Hydrophobic

hydrophilic like water water, hydrophobic water hate oil

Functions of the cytoplasmic membrane

a) permeability barrier: gateway for transport nutrients

b)Protein anchor: Proteins in transport

c)Energy conservation: Generation and dissipation of the proton

what is Transport proteins

accumulate solutes, high selectivity and High specificity

say the types of Carbohydrates

Monosachharides, Disaccharides, Polysaccharides , dehydration reaction

explain monosaccharides

Glucose (blood sugar) , galactose (sugar in milk) , fructose (sugar in honey)

explain dehydration reaction

if We have two molecules, they combine and lose water molecules

explain disaccharides

Structural isomers composed of hexoses.

sucrose (table sugar), lactose (sugar milk), maltose (starch digestion)

explain polysaccharides

polymers of tens to hundreds units

Glycogen (broken back down intro glucose when energy us needed), cellulose (abundant organic molecule in biosphere

What are the proteins?

cell ranges between 40 and 60% of dry weight , functions: transport, enzymes, adhesion motion

Basic structure of an amino acid - protein

Aminoacids determine how is going to be protein, the protein is the transport

molecules containing an amine grupo, a carboxylic acid group and a side-chain

Gregor mendel and his peas

1850-mendel performed collect data and uncover the basis principles of genetic

When the chromosomes were discovered?

1800s

Who discovered the structure of DNA

James Watson and Francis Crick in 1953 but its supposed that they steal the idea of Rosalind Franklin

What is DNA (deoxyribonucleic acid ) and RNA(ribonucleic acid)

macromolecules composed of monomers called nucleotides

What is a nucleotide base?

They stole tour information to tell your cells how its supposed to work

Mention the Chargarff’s rules

DNA should have a 1:! ratio of pyrimidine and purine bases

The amount of guanine is equal to cytosine and the amount of adenine is equal to thymine