Test Review 2

Bio-241 Microbiology

Define metabolism

The sum of energy and chemical changes in a cell

Define energy

a property of objects which can be transferred to other objects or converted into different forms, but cannot be created or destroyed

What is the difference between potential and kinetic energy?

Energy associated with the motion of an object is called kinetic energy. 

Energy stored in an object due to its position is called potential energy.

List the 5 types of energy

Chemical

thermal

kinetic

potential

Solar

Define calorie

(unit of heat)

How are calories measured?

Measure by the amount of heat needed to raise 1 gram or 1 milimeters of water 1 °C 

What is the relationship between a kilocalorie and a calorie?

1 kcal = 1000 calories

Define chemical change

Molecules are reaaranged to form a new molecule

State the Law of Conservation of Matter

Matter can not be created or destroyed. The same amount of matter exists before and after any physical or chemical change.

What factors increase collisions of substances during chemical reactions?

Heat is the main factor that increase collisions of substances during chemical reactions. However, also in an increase in the concentration of the reactants cause a increase in collisions.

What are the two divisions of metabolism?

Catabolism and anabolism

What is the difference between catabolism and anabolism?

Catabolism is to destroy or decompose large molecules to smaller ones. Where’s Anabolism is to build up and create smaller molecules into bigger ones.

What is the difference between a hydrogen ion and the hydrogen atom?

A hydrogen atom has one electron and one proton. A hydrogen ion is created when a hydrogen atom loses an electron

Identify examples of catabolism and anabolism

**What are electron carriers ?**

**Molecules that carry 2 electrons and either 1 or 2 hydrogen ions**

List the 3 types of electron carriers found in most cells.

NAD (Nicotinamid adenine dinucleotide)

NADP (Nicotinamid adenine dinucleotide Phosphate)

FAD ( flawin)

What is the difference between the oxidized and reduced form of each electron carrier?

NAD- is not carrying the 2 electrons or a single hydrogen ion

NADM- carries 2 electrons and a single hydrogen ion

FAD - is not carrying the 2 electrons or 2 hydrogen ions

FADM: carries 2 electrons and a hydrogen ion

List 4 characteristics of enzymes

==Organic molecules== – most enzymes are made of proteins, but some are made of ribonucleic acid

==Catalysts== – substances that speed up a chemical reaction but are not changed permanently in the chemical reaction

==Lowering the activation energy== – energy required to disassemble molecules so that they can recombine to form new molecules

denoted by the suffix “ase”

What is the difference between a simple enzyme and a conjugated enzyme

Simple enzymes – only made of protein

Conjugated enzymes – only made of protein and some other nonprotein molecules

-Holoenzymes – protein part + nonprotein part

-Apoenzymes (Cofactor) – nonprotein part (Metal ion or coenzyme)

List 2 types of cofactors found in biochemical systems.

Metal ion – magnesium, copper, iron, etc.

Coenzyme – organic molecule (eg. Vitamins

Identify the two parts of a conjugated enzyme

What is the relationship between the substrate and the active site of an enzyme?

The substrate is a substance acted upon by the enzyme and the active site is place on the enzyme where the substrate combines.

Define active site

Active site – place on the enzyme where the substrate combines

Define substrate.

S = Substrate – substance acted upon by the enzyme

What is the function of a catalyst

a substance that speeds up a chemical reaction

What is the fate of E and S in the enzymatic equation, E + S -> ES -> E + P?

One substrate can be broken into 2 products (catabolism) or two substrates can combine to form 1 product (anabolism)

A catalyst is a substance (as an enzyme) that enables a chemical reaction to proceed at a usually faster rate under different conditions (as at a lower temperature) than otherwise possible.

Catalase converting hydrogen peroxide to water and oxygen (at a high rate)

For interaction of enzyme and substrate to occur, a substrate must have a correct

Identify the parts of an enzymatic reaction in a chemical reaction that involves an enzyme

Define activation energy

the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.

How are enzymes denoted?

denoted by the suffix “ase”

Explain why enzymes are characterized as highly specific.

each enzyme catalyzes only one type of reaction in only one compound or a group of structurally related compounds. The compound or compounds on which an enzyme acts are known as its substrates.

What is the difference between an endoenzyme and an exoenzyme?

exoenzymes are transported extracellularly \n \n endoenzymes are retained intracellularly and function there

Describe the structure of adenosine triphosphate.

consisting of a nitrogenous base (adenine), a ribose sugar, and three serially bonded phosphate groups. 

List 2 differences between ADP and ATP.

What is the chemical formula for ribose?

C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H.

What are the differences between substrate level phosphorylation and chemiosmosis?

30-32 molecules of ATP are generated by chemiosmosis during breakdown of one molecule of glucose. Whereas only about 8 molecules are formed through substrate level phosphorylation, that is transfer of a high energy phosphate group from a substrate to ADP.

What is the function of ATP synthase?

 to synthesize ATP from ADP and inorganic phosphate (Pi) in the F1 sector.

How many ATP are generated from NADH and FADH2 during chemisosmotic phosphorylation?

only two ATP molecules

What is the difference between a phosphoryl shift and phosphoryl transfer?

 Phosphoryl transfer is the name given to the chemical process of the transfer of the phosphoryl group (PO3) from a phosphate ester or anhydride to a nucleophile.

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phosphoryl shift is a shift in the conversion of 3-phosphoglycerate into 2-phosphoglycerate.

What is the difference between oxidation and reduction?

Oxidation is when the total number of electrons increases in a reaction

reduction is when the total number of electrons decreases in a reaction.

List 3 characteristics of glucose

* It's called simple sugar due to its monosaccharide.
* The chemical formula of glucose is C6H12O6.
* IUPAC's name for glucose is D-glucose.

Identify examples of each of the 7 chemical reactions of metabolism in Glycolysis and the Kreb Cycle.

List the products formed during Glycolysis and the Kreb Cycle.

In glycolysis, two ATP were invested, and four ATP and two NADH+H+ were produced.

In the Krebs cycle, two ATP, six NADH +H+, and two FADH2 were produced.

List the products formed in the Electron Transport Chain.

ATP, NAD+, FAD, water, and protons.

Explain what happens to pyruvate during the transition steps in cellular respiration ?

The transition reaction converts the two molecules of the 3-carbon pyruvate from glycolysis (and other pathways) into two molecules of the 2-carbon molecule acetyl Coenzyme A (acetyl-CoA) and 2 molecules of carbon dioxide.

What is the difference between the role of an electron carrier and that of a coenzyme?

Describe the changes associated with pyruvate during the Transition Steps?

Before pyruvate can enter the next stage of cellular respiration it needs to be modified slightly. The transition reaction is a very short reaction which converts the two molecules of pyruvate to two molecules of acetyl CoA, carbon dioxide, and two high energy electron pairs convert NAD to NADH.

What is the difference between fermentation and anaerobic respiration?

Fermentation uses glycolysis only.

Anaerobic respiration uses all three parts of cellular respiration, including the parts in the mitochondria like the citric acid cycle and electron transport.

Define aerobic respiration.

(includes Glycolysis, Transition Steps, Krebs Cycle, Electron Transport Chain). The

final electron acceptor is oxygen

Write the summary equation for photosynthesis.

6CO2 + 6H2O → C6H12O6 + 6O2.

What is the role of oxygen in photosynthesis and aerobic respiration?

In Photosynthesis, Oxygen is released as a byproduct. 

In cellular respiration, oxygen is used to break down glucose, releasing chemical energy and heat in the process.

What is the difference between the ground and excited state?

The ground state configuration is the lowest energy, most stable arrangement. An excited state configuration is a higher energy arrangement

What is the difference between magnesium in the ground state and the excited state?

1s22s22p63s13p1 represents an atom of magnesium in an excited state. \n The ground state electronic configuration is 1s22s22p63s2. One electron is transferred from 3s to 3p level to form excited state. Mg has atomic number of 12. Thus it will have 12 electrons.

Define pigment?

substances that reflect the wavelength of light they cannot absorb (algae and blue-green algae, the reflected light we see color)

Identify the origin of electrons, the replacement electrons and the final electron acceptors in Photosystems II and 57. I of noncyclic photophosphorylation.

Light Dependent Reactions (Light Reactions) proceed only in the presence of light

(a) Noncyclic photophosphorylation – involves P680 (Photosystem II); generates molecular oxygen, NADPH, and ATP (680 wavelength is the highest to excite electrons)

(b) Cyclic photophosphorylation – involves only P700 (photosystem I); generates ATP

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Light Independent Reactions (Dark Reactions) proceed in the absence or presence of light

(a) Calvin Cycle uses ATP and NADPH generated during the light reactions to synthesize glucose and other organic molecules.

(b) 2 electrons ejected from PS II upon reaction to sunlight, it goes to PS I, where it is ejected again until they get to the final destination NADP+. From H2O -> ½ O2 + 2H rxn.

(c) Sun hits both P680 & P700 (chlorophyll clusters). The original electrons from P680 comes from water. The original electrons for P700 comes from P680. Final destination for electrons leaving P680 is P700. Final destination for electrons leaving P700 is NADP (enzyme: Pyridine nucleotide reductase)

(d) For cyclic, only ATP is generated, no NADPH.

List the products of noncyclic photophosphorylation.

What happens during the Hill Reaction?

Water is split into hydrogen and oxygen; the electrons released from hydrogen are used as replacement electrons for Photosystem II (P680)

What is the difference between anoxygenic an oxygenic photosynthesis?

Oxygenic photosynthesis – oxygen releasing because the replacement electrons come from the hydrogen in water (H2O)

Anoxygenic photosynthesis – non-oxygen releasing, because the replacement electrons come from the hydrogen in compounds such as hydrogen sulfide (H2S)

Define microbial growth

an increase in the number of cells in a population

What are the differences between budding and binary fission?

Fission – the splitting of a parent cell into two (2) genetically-identical daughter cells.

Budding – the outgrowth or projection of a parent cell called a bud differentiates into a single () genetically identical daughter cell (hydra or yeast-eukaryotic cell)

Define fragmentation.

the breakage or fragmentation of a filamentous multicellular individual. Each

piece continues to thrive as a separate individual (spirogyra)

Define temperature.

The average kinetic energy or degree of hotness of a system

Define psychrophile, mesophile, and thermophile

Psychrophiles – requires cold temperatures for growth (-4 C to 22 C)

2\. Mesophiles – requires moderate temperatures for growth (12 C to 45 C)

3\. Thermophiles – requires hot temperatures for growth (42 C to 72 C) – can’t reproduce in body

(a) Extreme thermophiles – require extremely hot temperatures for growth (62 C – 120 C)

\- Water freezes a 0 C; water boils at 100 C, normal body temperature is about 37 C.

What is the difference between the minimum and maximum temperature for growth?

Minimum temperature required for growth – lowest temperature (some organisms like bacteria and fungi can live at temperature below the minimum but they will not be able to reproduce or grow and will not die

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Maximum temperature required for growth – highest temperature (will reproduce slowly, but above the maximum you will kill them)

Define optimum temperature for growth.

best temperature

Define buffer

substances that resist changes in pH

How are hydrogen and hydroxyl ions symbolized?

Hydrogen ion=H+

Hydroxyl ion=OH−

Define pH

measurement of the hydrogen ion concentration of a solution

What is the difference between an acidic and basic solution?

Acidic solutions have a high concentration of hydrogen or hydronium ions.

In contrast, basic solutions have a lower concentration of hydronium ions and a higher concentration of hydroxide ions.

Describe a neutral solution.

Neutral solutions are those in which the concentrations of hydrogen and hydroxide ions are the same

What is the relationship between the pH scale and the hydrogen ion concentration of a solution?

The overall concentration of hydrogen ions is inversely related to its pH and can be measured on the pH scale (Figure 1). Therefore, the more hydrogen ions present, the lower the pH; conversely, the fewer hydrogen ions, the higher the pH. The pH scale ranges from 0 to 14.

Give some examples of acids and bases.

Define *per cent*?

means part per 100 parts

How do you prepare a *per cent* solution?

How do you prepare a 8% NaCl solution?

8 parts NaCl / 8 parts NaCl + 92 parts H2O or Add 8 parts NaCl to 92 parts H2O

What is the difference between a dilute and a concentrated solution?

dilute solution” refers to a solution in which a small amount of solute is dissolved in a large amount of solvent. The term “concentrated solution” refers to a solution in which the amount of solute dissolved is more compared to the amount of solvent.

Define osmosis

Water moves from a high concentrated to a low concentration and continues until the two solution are equal in concentration

What is the difference between an acidophile and a halophile?

acidophiles-microorganisms that live in high concentration of acids

halophile-microorganisms that live in high salt concentrations. Includes Archaea, Bacteria, Fungi, and Algae species.

What are the differences between a hypotonic and hypertonic solution?

Hypertonic – high concentration; water moves out of the cell causing the cell to shrink/the decrease in size

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low concentration; water moves into the cell causing the cell to increase in size – it may swell and even burst

Define isotonic.

Isotonic – same concentration; water moves in and out of the cell at the same rate – cell remains the same size

What are the carbon and energy sources for a photoheterotroph, chemoheterotroph, photoautotroph, and a chemoautotroph?

Photoautotroph – use light as the energy source and carbon dioxide as the carbon source (algae,

bacteria, plants)

4\. Photoheterotroph – use light as the energy source and carbon-containing compounds other than

carbon dioxide as the carbon source (bacteria, archaea)

5\. Chemoautotroph – use inorganic substances as the energy source and carbo dioxide as the

carbon source (archaea, bacteria)

6\. Chemoheterotroph – use carbon-containing compounds other than carbon dioxide as the carbon

source and energy sources (bacteria, archaea, protozoa, fungi, animals)

Why are carbonates used in a culture medium?

put in medium sodium carbonate or sodium bicarbonate (CO2 would go in

atmosphere if put in medium, but CO3 will release CO2 when added to water

Give some examples of carbonates?

calcite or calcium carbonate, CaCO3

What is the difference between an obligate anaerobe and an obligate aerobe?

Obligate aerobes – strict requirement for oxygen

Obligate anaerobe – cannot live in the presence of oxygen (Clostridium botulinum – botulin) – Gram-positive bacteria in this group, will O2 will kill vegetative cell but not the endospore (can be found in swamps, deep in soil, in caves, causes diseases in people)

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Define facultative anaerobe.

Facultative anaerobe – can live in the presence or absence of oxygen; if oxygen is present it uses it

What is the difference between an aerotolerant anaerobe and a microaerophilic organism?

Aerotolerant anaerobe – can live in the presence of oxygen but do not use it

Microaerophilic – requires very small amounts of oxygen (in large O2 it will kill it)

Identify the elements in proteins and nucleic acids.

Nucleic acids contain the same elements as proteins: carbon, hydrogen, oxygen, nitrogen; plus phosphorous (C, H, O, N, and P)

What are organic growth factors? List some examples of organic growth factors?

Growth factors are organic compounds.

Such as amino acids , purines , pyrimidines , and vitamins

Define fastidious.

has very complicated nutritional requirements

What is agar?

A solidifying agent, consisting of a polysaccharide derived from certain marine alga that cannot be digested by most organisms

Why is agar used in a culture medium?

When heated to 100 C, then cool it down, forms something that isharder than Jell-O, it is a semi-solid. Reason for growing bacteria in semi-solid, is so that bacteria will just grow on the surface, and we can scoop off from the surface without any of the nutrients from the broth… pure bacteria or fungus

What is the difference between a broth and a semi-solid culture medium?

(a) Liquid – broth

(b) Semi-solid (broth + agar)

What is the difference between a culture and a culture medium?

\-Culture medium: nutrients required for growing microorganisms in the laboratory \n -Culture: microorganisms growing in a culture medium

What is the difference between chemically-defined and a complex medium?

\-Chemically-defined: you know the exact chemical composition of every ingredient in the culture medium \n -Complex: you do not know the exact chemical formula of every ingredient in the culture medium. It varies from batch to batch.

Why are peptones, tryptones, and other *–one* compounds added to a culture medium?

They contain C, H, O, N, and S

What is the difference between a selective and differential media?

* selective media are used to isolate a particular strain of microorganisms whereas


* differential media are used to identify and differentiate a closely-related group of microorganisms.

Why is velvet used to replica-plate?

elveteen is utilized in the replica plating of yeast cells. The velveteen's texture allows the cells to be copied to a new plate exactly without morphing the appearance or location of a colony.

What is the difference between a pure and mixed culture?

\-Pure Culture: contains only one type of microorganism growing in a culture medium \n -Mixed culture: contains more than one type of microorganism growing in a culture medium (soil, food, water, feces, saliva, air)

Define streak plating.

rub a thin line of the specimen over the surface of a spread (agar) plate.

Define colony

descendants of a single cell that landed in a region (clones)

Define generation time.

time it takes a cell to divide.

Identify the symbols in b = B \* 2n.

\-b: final concentration of cells \n -B: initial concentration of cells \n -n: number of doublings/generations