Microbio lesson #2

The structure of an atom are composed of?

• Electrons: negatively charged particles

• Protons: positvely charged particles

• Neutrons: uncharged particles 

What are negatively charged particles?

electrons

What are positvely charged particles?

protons

What are uncharged particles?

neutrons

The 4 macromolecules

Carbs

Lipids

Proteins 

Nucleic acids

The elements of life:

• CHONPKS (how to remember)

• Hydrogen (H)

• Carbon (C) 

• Nitrogen (N)

• Oxygen

• Sodium

• Magnesium

• Phosphorus 

• Sulfur

• Chlorine

• Potassium

• Calcium

• Iodine

• Iron

Identify this:

• Serve as cell structures and cellular energy sources

  • Serve as cell structures because carbs are part of the cell wall 

• Include sugars and starches 

• Consist of C, H, and O with the formula (CH₂O)_n

• Many carbs are isomers

  • Isomer: same chemical formula different structural formula 

  • Molecules with the same chemical formula, but different structures 

• The major energy givers for the cell

  • Cells utilize carbs for energy 

  • All living cells get energy by breaking sugars (carbs)

Carbohydrates (CH₂O)_n

Identify this:

• Monosaccharides are simple sugars with three to seven carbon atoms

  • Glucose and deoxyribose are examples of common monosaccharides

monosaccharides

Identify this:

• Formed when two monosaccharides are joined in a dehydration synthesis

  • dehydration synthesis: A chemical reaction in which a molecule of water is released; also called condensation reaction.

• Disaccharides can be broken down by hydrolysis

  • Disaccharides can be broken down into smaller, simpler molecules when water is added. This chemical reaction, the reverse of dehydration synthesis, is called hydrolysis

Disaccharides

Identify this:

• Consist of tens of hundreds of monosaccharides joined through dehydration synthesis 

  • Starch , glycogen, dextran, and cellulose are polymers of glucose that differ in their bonding and function

polysachharides

What is being descibed here:

• Primary components of cell membrane

• Consist of C, H, and O

• Are nonpolar and insoluble in water

  • they stay away from water molecules 

• Can give some energy

lipids

What is a simple lipid?

• Fats or triglycerides 

• Contain glycerol and fatty dehydration synthesis 

What is saturated fat?

 no double bonds in the fatty acids

What is unsaturated fat?

• one or more double bounds in the fatty acids

  • Cis: H atoms on the same side of the double bond

  • Trans: H atoms on opposite sides of the double bond 

What is a complex lipid?

• Contain C, H, and O + P, N, and/or S

• Cell membranes are made of complex lipids called phospholipids

  • Glycerol, two fatty acids, and a phosphate group

    • One side water loving one side water hating

• Phospholipids have polar as well as nonpolar regions 

  • Polar heads(Hyrophilic): water loving side 

  • Nonpolar tails (hydrophobic): water hating side 

What is a steriod?

• Four carbon rings with an- OH group attached to one ring

• Part of membranes that keep the membranes fluid 

  • Cholesterol: a steroid 

    •  Has a closed ring structure 

What is a protein?

• Made of C, H, O, N and sometimes S

• Essential in cell strucuture and function

  • Enzymes that speed up chemical reactions

    • They participate in all of cellular reactions 

  • Transporter proteins that move chemicals across membranes

  • Flagella that aid in movement

  • Some bacterial toxins and cell structures 

• We have 20 different amino acids

  • Only 2 contain sulfur 

    • Amino acid: mentinionine and cystine

• 99% of biological catalysts are proteins

What is a…

• Proteins(polymer) consists of subunits called amino acid(monomer)

• Amino acids contain an alpha-carbon that has an attached

  • Carboxyl group

    • (-COOH)

  • Amino group

    • (NH₂)

  • Side group

amino acid

Amino acids acids exist in either of two …

• Stereoisomers: D or L

• L-forms are most often found in nature 

• All amino acids have NH

each protein becomes different by

arrangement of amino acid 

Protein structure

1. Primary structue: polypeptide strand (amino acid sequence)

2. Secondary structure: helix and pleated sheet (with three polypeptide strand)

3. Tertiary structure: helix and pleated sheets fold into a 3D shape

4. Quaternary structure: the relationship of several folded polypeptide chains, forming a protein 

extra info:

polypeptide is a big chain

a Peptide bond is between carboxyl group and amino group

What are nucleotides?

• Consist of nucleotides

• Nucleotides consists of 

  • Five-carbon (pentose) sugar

  • Phosphate group

  • nitrogen -containing (purine or pyrimidine) base

    • A=T/U 

    • G=C

    • A & G : pyrimidine

    • T/U & C purine 

• Nucleosides consist of 

  • Pentose

  • Nitrogen-containing base 

• 2 types in all living cells

  • DNA and RNA

What is DNA?

• Deoxyribonucleic acid

  • Contains deoxyribose

  • Exists as a double helix

  • Adenine hydrogen bonds with thymine

  • Cytosine hydrogen bonds with Guanine

• Order of the nitrogen-containing bases forms the genetic instructions of the organism 

• Strands are complementary ,and parallel to each other 

What is RNA?

• Ribonucleic acid

  • Contains ribose

  • Is single-stranded 

  • Adenine hydrogen bonds with Uracil 

  • Cytosine hydrogen bonds with Guanine

• Several kinds of RNA play a specific role in protein synthesis 

Functional molecules:

• Riobosomal RNA (r- RNA)

• Transfer RNA (t-RNA)

• messenger RNA (m-RNA)

  • carries message for protein to be made

A uracil nucleotide of RNA

• Uracil

• Phosphate 

• Ribose

  • When it becomes a deoxyribose sugar the O from OH on the right side, is removed

Adenosine Triphosphate (ATP)

• Stores the chemical energy released by some chemical reactions

• Releases phosphate groups by hydrolysis to liberate useful energy for the cell

What is dehydration synthesis?

a chemical reaction in which a molecule of water is released; also called condensation reaction

What is hydrolysis?

Disaccharides can be broken down into smaller, simpler molecules when water is added. This chemical reaction, the reverse of dehydration synthesis, i

What is a covalent bond?

• atoms share pairs of electrons

• they stronger than ionic bonds and are far more common in organic molecules

What is an ionic bond?

• A chemical attraction between ions of opposite charge

• A positively or negatively charged atom or group of atoms is called an ion.

• To form this bond, one ion is an electron donor, and the other ion is an electron acceptor.

What is an isomer?

two molecules with the same chemical formula but different structures and properties

what is a cis fatty acid?

H atoms on the same side of the double bond

What is a trans fatty acid?

H atoms on opposite sides of the double bond 

What is the strongest chemcial bond?

covalent bond

the science of interaction between atoms and molecules is called?

chemistry

the metabolic activites of microorganisms involve complex?

chemical reactions

Microbes break down nutrients to obtain energy and to make?

new cells

What is the the smallest unit of a chemical element that exhibits the properties of that element.

atom

Atoms consist of a nucleus, which contains?

protons and neutrons, and electrons, which move around the nucleus

The atomic number is the number of….

protons in the nucleus

the total number of protons and neutrons is the ….

atomic mass

Atoms with the same number of protons and the same chemical behavior are classified as the same

chemical elements

Atoms that have the same atomic number (are of the same element) but different atomic masses are called

isotopes

In an atom, electrons are arranged around?

the nucleus in electron shells

Each shell can hold a characteristic maximum number of

electrons

the chemical properties of an atom are due largely to the number of

electrons in its outermost (valence) shell

molecules are made up of …

two or more atoms

molecule consisting of at least two different kinds of atoms are called?

compounds

Atoms form molecules in order to fill their……

outermost electron shell

Attractive forces that bind two atoms together are called

chemical bonds

The combining capacity of an atom—the number of chemical bonds the atom can form with other atoms—is its

valence

A positively or negatively charged atom or group of atoms is called an

ion

How are ionic bonds formed?

one ion is an electron donor, and the other ion is an electron acceptor

In a covalent bond atoms share…

pairs of electrons

A hydrogen bond exists when a hydrogen atom….

covalently bonded to one oxygen or nitrogen atom is attracted to another oxygen or nitrogen atom

Hydrogen bonds form….

weak links between different molecules or between parts of the same large molecule

What is the sum of the atomic massses of all the atoms in a molecule?

molecular mass

A mole of an atom, ion, or molecule is equal to its….

atomic or molecular mass expressed in grams

Chemical reactions are the making or breaking of…

chemical bonds between atoms

A change of energy occurs during?

chemical reactions

What requires more energy than they release?

endergonic reactions

What reactions release more energy?

exergonic reactions

In a synthesis reaction, atoms, ions, or molecules are combined to form a

larger molecule

In a decomposition reaction, a larger molecule is broken down into its component…

molecules, ions, and atoms

What happens in an exchange reaction?

two molecules are decomposed, and their subunits are used to synthesize two new molecules

The products of reversible reactions can do what?

readily revert to form the original reactants

inorganic compounds are usually..

small, ionically bonded molecules

What is the most abundant substance in cells?

water

Because _____ is a polar molecule, it is an excellent solvent

water

What substance is a reactant in many of the decomposition reactions of digestion?

water

What substance is an excellent temperature buffer?

water

An acid dissociates into?

H+ and anions

A base dissociated into?

OH^- and cations

A salt disociates..

into negative and positive ions, neither of which is H⁺ or OH^-

What term refers to the concentration of H⁺ in a solution?

pH

A solution of pH 7 is

neutral

A pH value below 7 indicates?

acidity

pH above 7 indicates?

alkalinity

The pH inside a cell and in culture media is stablilized with?

pH buffers

Organic compounds always contain?

carbon and hydrogen

Carbon atoms form up to..

four bonds with other atoms

Organic compounds are mostly or entirely

covalently bonded

A chain of carbon atoms forms a

carbon skeleton

Functional groups of atoms are responsible for most of the properties of

organic molecules

The letter R may be used to denote the remainder of an

organic molecule

Frequently encountered classes of molecules are

R─OH (alcohols) and R─COOH (organic acids)

Small organic molecules may combine into very large molecules called

macromolecules

Organic molecules may be broken down by?

hydrolysis, a reaction involving the splitting of water molecules

Carbohydrates are compounds consisting of atoms of

carbon, hydrogen, and oxygen, with hydrogen and oxygen in a 2:1 ratio

Monosaccharides contain how many atoms?

three to seven

Example of isomer

glucose (C6H12O6) and fructose (C6H12O6).

Monosaccharides may form what by dehydration synthesis

disaccharides and polysaccharides

Lipids are a diverse group of compounds distinguished by their

insolubility in water

Simple lipids consist of a molecule of

glycerol and three molecules of fatty acids.

Phospholipids are complex lipids consisting of

glycerol, two fatty acids, and a phosphate group

Steroids have four interconnected…

carbon ring structures

Sterols have a functional…

hydroxyl group

What are the building blocks of proteins?

amino acids

Amino acids consist of

carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur

How many amino acids occur naturally in proteins

twenty