Microbiology Lec: Chemistry and Biomolecules

MICROBIOLOGY LEC EXAM 1

What is Chemistry?

It is the study of the interactions between atoms and molecules

What is considered the smallest unit of matter?

Atoms

What term describes two or more atoms bonded together?

Molecules

Which subatomic particle carries a positive charge, is weighted, and is located in the nucleus?

Proton

What are neutrons?

Uncharged particles, weighted

Which subatomic particle carries a negative charge, is unweighted, and is located in an atom?

Electrons

What is the atomic number?

Number of protons (Unchanged)

How is the atomic mass of an atom calculated?

Protons + Neurons

What are isotopes?

Atoms with a different number of neurons

What are ions?

Atoms that have gained or loss electrons

What atomic property describes an atom's ability to attract electrons?

Electronegativity

Electronegativity determines what?

Chemical bonding

Name the types of chemical bonds

Ionic

Covalent

Hydrogen

What occurs during an ionic bond?

An electron is transferred from one element to another

Under what condition of electronegativity do ionic bonds typically form?

They form between one atom with strong electronegativity and one with weak electronegativity

Ionic bonds occur between two ions that possess blank charges

Opposite

Example of ionic bond

Sodium chloride (NaCl)

What occurs during a covalent bond?

Electrons are shared between atoms

Covalent bonds generally form between atoms with blank electronegativity values

Relatively equal

What is the difference between a non-polar and a polar covalent bond?

Non-polar bonds involve equal sharing of electrons, whereas polar bonds involve unequal sharing

Example of non-polar covalent bond

Methane (CH4)

Example of polar covalent bond

Water (H2O)

What occurs during a hydrogen bond?

Attraction between opposite partial charges on the adjacent molecules

In a water molecule, near which atom is the slight positive charge?

Hydrogen

In a water molecule, near which atom is the slight negative charge?

Oxygen

Example of hydrogen bond

Water molecules binding to each other

What are the three main categories of chemical reactions in biology?

Synthesis

Decomposition

Exchange

What is the metabolic term for synthesis reactions that build larger molecules?

Anabolism

Synthesis reactions are classified as blank and explain the definition of the blank

Endergonic, Energy consuming

Example of synthesis

Dehydration synthesis

What is the metabolic term for decomposition reactions that break down molecules?

Catabolism

Decomposition reactions are classified as blank and explain the definition of the blank

Exergonic, energy releasing

Example of decomposition

Hydrolysis

What is an exchange reaction?

It is a reaction that is part synthesis and part decomposition

What is the difference between inorganic and organic molecules?

Inorganic molecules lack carbon, while organic molecules always contain carbon and hydrogen

Which unique property of the water molecule leads to hydrogen bonding?

Its polarity

What are the functions of water?

Acts as a temperature buffer

Unique density

Serves as a solvent (Dissolving agent)

Is a reactant/product in reactions

What is a solvent?

A dissolving agent

How do acids behave when placed in an aqueous solution?

They release hydrogen ions (H+)

What is the acid pH value?

Below 7

Example of acid

Hydrogen chloride (HCI)

How do bases behave when placed in an aqueous solution?

They release hydroxide ions (OH-)

What is the base pH value?

Above 7

Example of base

Sodium hydroxide (NaOH)

What is salt?

An ionic compound that dissociates in water without releasing H+ (Water) or OH- (Hydroxyl)

What does pH stand for?

Potential of hydrogen

What is the mathematical formula used to calculate pH?

pH = -log[H+]

What is the pH scale?

0-14

What is considered acidic on the pH scale?

Below 7

What is considered neutral on the pH scale?

7

What is considered basic on the pH scale?

Above 7

What are the four main classes of biomolecules?

Carbohydrates

Lipids

Proteins

Nucleic acids

What three elements are always found in lipids?

Carbon

Hydrogen

Oxygen

Carbohydrates are generally polar, making them blank

Hydrophilic (Water-loving)

Name the types of carbohydrates

Simple sugars

Complex carbohydrates

What is the function of simple sugars?

Providing fast energy

What is a monosaccharide?

A carbohydrate composed of one single sugar unit

Examples of monosaccharide

Glucose and Fructose

What is a disaccharide?

A carbohydrate composed of two sugar units

Examples of disaccharides

Sucrose and lactose

What are the functions of complex carbohydrates?

Energy storage

Structural support

Acting as cell membrane components

Example of complex carbohydrate

Polysaccharide

What is a polysaccharide?

Chain of sugars

Examples of polysaccharides

Starch

Glycogen

Cellulose

Dextran

Chitin

Lipids are generally non-polar, making them blank

Hydrophobic (Water-fearing)

Name the types of lipids

Triglycerides

Phospholipids

Steroids

What is the chemical structure of a triglyceride?

One glycerol molecule bonded to three fatty acid chains

What are the functions of triglycerides?

Energy storage

Insulation

Protection

Name the types of triglycerides

Saturated

Unsaturated

What structural feature characterizes a saturated fatty acid?

It has no double bonds between carbon atoms

Saturated fats are typically blank at room temperature because they are tightly packed

Solid

What structural feature characterizes an unsaturated fatty acid?

It contains one or more double bonds

Unsaturated fats are typically blank at room temperature because they are loosely packed

Liquid

What are the three components of a phospholipid molecule?

Glycerol

Polar phosphate group

Two non-polar fatty acid tails

What is the function of phospholipids?

Forming the structure of cell membranes (Bilayers)

What is the chemical structure of all steroids?

4 carbon rings with side chains

From which specific lipid are all steroids derived?

Cholesterol

Examples of steroids

Cholesterol

Testosterone

Vitamin D

What are the functions of steroids?

Membrane fluidity

Cellular communication

What four elements are always found in proteins?

Carbon

Hydrogen

Oxygen

Nitrogen

Proteins are defined as chains of blank connected by peptide bonds

Amino acids

What are the functions of proteins?

Structural support

Enzymatic activity

Chemical messengers

Receptors

What are the four components of an amino acid's structure?

Central carbon

An amino group (NH2)

A carboxyl group (COOH)

A R group

What does the R Group do?

Determines amino acid

Name the levels of protein structure

Primary

Secondary

Tertiary

Quaternary

What does the primary structure of a protein represent?

The sequence of amino acids in the polypeptide chain

What specific type of bond maintains the primary structure of a protein?

Peptide bonds

What two repetitive shapes characterize the secondary structure of proteins?

Alpha helix (Spirals)

Beta-pleated sheets (Pleats)

Which type of bond is responsible for creating the secondary structure of a protein?

Hydrogen bonds

What does the tertiary structure of a protein describe?

3D folding of the polypeptide

Which three types of bonds involve the R groups to stabilize a protein's tertiary structure?

Hydrogen

Ionic

Disulfide bonds

What is the quaternary level of protein structure?

Multiple polypeptide chains binding together

What bonds are involved in the quaternary structure?

Hydrogen

Ionic

Disulfide

What five elements are always found in nucleic acids?

Carbon

Hydrogen

Oxygen

Nitrogen

Phosphorus

What are the functions of nucleic acids?

Storing genetic information

Enabling DNA expression

Serving as energy currency

Name the types of nucleic acids

DNA

RNA

ATP

What are the three structural components of a nucleotide?

Phosphate group

Pentose sugar

Nitrogenous base

Adenine and Guanine are classified as blank nitrogenous bases

Purine

Cytosine, Thymine, and Uracil are classified as blank nitrogenous bases

Pyrimidine

What is the difference between DNA and RNA?

DNA contains deoxyribose, while RNA contains ribose