Microbiology > Ch. 2 > Flashcards

Ch. 2 Flashcards

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1
Q

What is matter?

A

Anything that occupies space and has mass.

Matter can exist in various states, including solid, liquid, and gas.

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2
Q

Define an atom.

A

Smallest unit of matter that retains element properties.

Atoms are the building blocks of all matter.

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3
Q

What subatomic particles make up an atom?

A
  • Protons (+)
  • Neutrons (0)
  • Electrons (-)

Protons determine the atomic number, while neutrons influence the mass number.

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4
Q

What is the atomic number?

A

Number of protons in an atom.

The atomic number identifies the element.

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5
Q

What is the mass number?

A

Sum of protons and neutrons in an atom.

It indicates the total mass of the atom.

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6
Q

What are isotopes?

A

Atoms with the same protons but different neutrons.

Isotopes can be stable or radioactive.

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7
Q

Which isotope is commonly used in medicine?

A

Iodine-131.

Iodine-131 is used for thyroid scans.

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8
Q

What do valence electrons determine?

A

Chemical reactivity.

Valence electrons are located in the outer shell of an atom.

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9
Q

Fill in the blank: Electron shells are like _______ and are stable when the outer shell is full.

A

orbits.

A full outer shell leads to lower energy and increased stability.

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10
Q

What are ionic bonds?

A

Transfer of electrons

Example: Na+ + Cl → NaCl (table salt)

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11
Q

Define covalent bonds

A

Sharing of electrons

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12
Q

What characterizes polar covalent bonds?

A

Unequal sharing, partial charges

Example: H2O

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13
Q

What characterizes nonpolar covalent bonds?

A

Equal sharing

Example: CH4

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14
Q

What are hydrogen bonds?

A

Weak attraction between H and electronegative atoms

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15
Q

What is the importance of hydrogen bonds in biological molecules?

A

Important in DNA base pairing and protein folding

A-T, G-C base pairing in DNA

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16
Q

How does water’s polarity affect its properties?

A

Excellent solvent

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17
Q

What is the effect of hydrogen bonding on water’s surface tension?

A

High surface tension, cohesion, adhesion

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18
Q

What role does water play as a temperature buffer?

A

Resists rapid temperature change

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19
Q

What is unique about ice compared to liquid water?

A

Ice is less dense than liquid water

This property insulates aquatic life

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20
Q

What is hydrolysis?

A

Breaks bonds with water

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21
Q

What is dehydration in chemical reactions?

A

Forms bonds, removes water

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22
Q

What is an acid?

A

H+ donor

Acids donate hydrogen ions in solution, affecting pH levels.

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23
Q

What is a base?

A

OH donor

Bases donate hydroxide ions in solution, influencing pH.

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24
Q

What is a salt?

A

Dissociates into ions

Salts are formed from the neutralization reaction between acids and bases.

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25
How is the pH scale calculated?
-log[H*] ## Footnote The pH scale measures the concentration of hydrogen ions in a solution.
26
What does each unit change on the pH scale represent?
10x change ## Footnote A change of one unit on the pH scale corresponds to a tenfold increase or decrease in hydrogen ion concentration.
27
What is the role of buffer systems?
Maintain pH ## Footnote Buffers resist changes in pH, helping to stabilize biological systems.
28
What is the approximate pH of blood?
~7.4 ## Footnote This slight alkalinity is crucial for proper physiological functions.
29
What pH level indicates acidosis?
Below 7.35 ## Footnote Acidosis can lead to various health issues and is a critical condition to monitor.
30
What pH level indicates alkalosis?
Above 7.45 ## Footnote Alkalosis can also cause significant health problems and requires medical attention.
31
What do all organic molecules contain?
C & H ## Footnote Carbon and hydrogen are the fundamental building blocks of organic compounds.
32
What functional group is represented by -OH?
Hydroxyl ## Footnote Hydroxyl groups are characteristic of alcohols.
33
What functional group is represented by -COOH?
Carboxyl ## Footnote Carboxyl groups are found in organic acids.
34
What functional group is represented by -NH?
Amino ## Footnote Amino groups are essential for the structure of proteins.
35
What functional group is represented by -PO4?
Phosphate ## Footnote Phosphate groups are vital for ATP and nucleic acids.
36
What process joins monomers to form polymers?
Dehydration synthesis ## Footnote This process involves the removal of water to create bonds between monomers.
37
What process breaks apart polymers into monomers?
Hydrolysis ## Footnote Hydrolysis involves the addition of water to break chemical bonds.
38
What is the composition ratio of carbohydrates?
C, H, O in 1:2:1 ratio
39
What is glucose commonly known as?
Blood sugar
40
What type of sugar is fructose?
Fruit sugar
41
What is galactose known as?
Milk sugar
42
What are disaccharides?
Sugars formed from two monosaccharides
43
What is sucrose made of?
Glucose + fructose
44
What is lactose composed of?
Glucose + galactose
45
What does maltose consist of?
Glucose + glucose
46
What is starch primarily used for in plants?
Storage
47
Where is glycogen primarily stored in animals?
Liver and muscle
48
What is cellulose and its role?
Plant cell walls, dietary fiber; humans can't digest
49
What is chitin and where is it found?
Fungal cell walls, exoskeleton of insects
50
Fill in the blank: Sucrose is also known as _______.
Table sugar
51
True or False: Humans can digest cellulose.
False
52
What are lipids?
Nonpolar, insoluble in water ## Footnote Lipids include various types such as fats, phospholipids, and steroids.
53
What is the structure of fats/triglycerides?
Glycerol + 3 fatty acids ## Footnote Triglycerides are a major form of fat storage in the body.
54
What are saturated fats characterized by?
No double bonds ## Footnote Saturated fats are typically solid at room temperature and are linked to heart disease.
55
What state are unsaturated fats typically in?
Liquid ## Footnote Unsaturated fats contain double bonds and are generally considered healthier than saturated fats.
56
What is the structure of phospholipids?
Glycerol + 2 fatty acids + phosphate ## Footnote Phospholipids are essential for forming cell membranes.
57
What do the hydrophilic heads and hydrophobic tails of phospholipids do?
Hydrophilic heads love water, hydrophobic tails hate water ## Footnote This property leads to the formation of bilayer membranes.
58
What is the basic structure of steroids?
4 carbon rings ## Footnote Steroids include important biological molecules such as cholesterol and hormones.
59
Name two types of hormones that are classified as steroids.
* Estrogen * Testosterone ## Footnote These hormones play critical roles in sexual development and reproduction.
60
Fill in the blank: Cholesterol is important for __________.
[membrane fluidity] ## Footnote Cholesterol helps maintain the integrity and fluidity of cell membranes.
61
What are the monomers of proteins?
Amino acids (20 common) ## Footnote Amino acids are the building blocks of proteins.
62
What are the three main components of an amino acid's structure?
Amino group, carboxyl group, R side chain ## Footnote The R side chain varies among different amino acids.
63
What type of bond links amino acids together?
Peptide bonds ## Footnote Peptide bonds are formed through a dehydration reaction.
64
What is the primary level of protein structure?
Sequence of amino acids ## Footnote The primary structure determines the protein's unique characteristics.
65
What are the two types of secondary structures in proteins?
Alpha-helix, beta-pleated sheet ## Footnote Secondary structures are stabilized by hydrogen bonds.
66
What defines the tertiary structure of a protein?
3D folding of the polypeptide chain ## Footnote Tertiary structure is influenced by ionic bonds, hydrogen bonds, and disulfide bridges.
67
What is quaternary structure in proteins?
Multiple polypeptides (e.g., hemoglobin) ## Footnote Quaternary structure involves the assembly of multiple polypeptide chains.
68
What is denaturation in proteins?
Unfolding due to heat or pH ## Footnote Denaturation can lead to loss of function in proteins.
69
What is sickle-cell anemia caused by?
One amino acid substitution ## Footnote This substitution leads to distorted red blood cells.
70
What are some functions of proteins?
Enzymes, transport, structural ## Footnote Examples include hemoglobin (transport), keratin, and collagen (structural).
71
What are the components of a nucleotide?
sugar + phosphate + nitrogenous base ## Footnote Nucleotides are the building blocks of nucleic acids.
72
What is the sugar present in DNA?
deoxyribose ## Footnote Deoxyribose distinguishes DNA from RNA.
73
What is the structure of DNA?
double helix ## Footnote DNA's structure resembles a twisted ladder.
74
What base pairs are found in DNA?
A-T, G-C ## Footnote Adenine pairs with Thymine, and Guanine pairs with Cytosine.
75
How is the DNA structure described in a word diagram?
Twisted ladder: sugar-phosphate = sides, H-bonds = rungs ## Footnote This analogy helps visualize the DNA structure.
76
What is the sugar present in RNA?
ribose ## Footnote Ribose is the sugar that differentiates RNA from DNA.
77
What is the structure of RNA?
single-stranded ## Footnote RNA typically exists as a single strand.
78
What replaces Thymine (T) in RNA?
Uracil (U) ## Footnote Uracil is used in place of Thymine in RNA.
79
What are the types of RNA?
mRNA, tRNA, rRNA ## Footnote mRNA is messenger RNA, tRNA is transfer RNA, and rRNA is ribosomal RNA.
80
Which viruses use RNA as genetic material?
some viruses (e.g., HIV) ## Footnote HIV is a well-known example of a virus that uses RNA.
81
What are the components of ATP?
Adenine + ribose + 3 phosphates ## Footnote ATP is a crucial energy carrier in cells.
82
What occurs during ATP hydrolysis?
ADP + Pi + energy ## Footnote Hydrolysis of ATP releases energy for cellular processes.
83
How long can ATP be stored in muscle?
only a few seconds ## Footnote ATP must be constantly regenerated to meet energy demands.
84
What contributes to ischemic cell death?
ATP depletion ## Footnote Lack of ATP can lead to cell death in ischemic conditions.
85
Define ionic bonds with examples
Ionic bonds are formed through the transfer of electrons from one atom to another, resulting in oppositely charged ions that attract each other. ## Footnote Example: Sodium chloride (NaCl) is formed from sodium (Na+) and chloride (Cl-).
86
Define covalent bonds with examples
Covalent bonds are formed when two atoms share one or more pairs of electrons. ## Footnote Example: Water (H2O) is formed by covalent bonds between hydrogen and oxygen atoms.
87
Define hydrogen bonds with examples
Hydrogen bonds are weak attractions between a hydrogen atom bonded to an electronegative atom and another electronegative atom. ## Footnote Example: Hydrogen bonds between water molecules contribute to its unique properties.
88
Why is water's polarity and hydrogen bonding essential?
Water's polarity and hydrogen bonding are essential for its solvent properties, high specific heat, and cohesion and adhesion characteristics.
89
A pH math: pH 7 → 4, how much 1 H*?
A change from pH 7 to pH 4 represents an increase of 1000 times in H+ concentration.
90
Differentiate mono/di/polysaccharides (examples)
Monosaccharides are single sugar units, disaccharides are two sugar units, and polysaccharides are long chains of sugar units. ## Footnote Examples: Glucose (mono), sucrose (di), starch (poly).
91
Compare saturated vs. unsaturated fats
Saturated fats have no double bonds between carbon atoms, while unsaturated fats have one or more double bonds. ## Footnote Saturated fats are typically solid at room temperature, unsaturated fats are usually liquid.
92
What are the levels of protein structure?
The levels of protein structure are primary, secondary, tertiary, and quaternary.
93
What is protein denaturation?
Denaturation is the process where a protein loses its natural structure due to external stress, affecting its function.
94
DNA vs. RNA differences
DNA is double-stranded, contains deoxyribose, and thymine; RNA is single-stranded, contains ribose, and uracil.
95
Why is ATP considered energy currency?
ATP is considered energy currency because it stores and provides energy for cellular processes.
96
What is the role of functional groups?
Functional groups determine the chemical reactivity and properties of organic molecules.
97
Why are phospholipids suited for membranes?
Phospholipids have hydrophilic heads and hydrophobic tails, allowing them to form bilayers that create cell membranes.
98
What medical uses do radioactive isotopes have?
Used in imaging, cancer treatment, and sterilization. ## Footnote Radioactive isotopes can help diagnose diseases and treat conditions such as cancer through targeted radiation.
99
How does the bicarbonate buffer maintain blood pH? What happens if it fails?
It neutralizes excess acids or bases to maintain pH; failure can lead to acidosis or alkalosis. ## Footnote The bicarbonate buffer system is crucial for maintaining homeostasis in blood pH levels.
100
Which disaccharide causes lactose intolerance?
Lactose. ## Footnote Lactose intolerance occurs due to the deficiency of the enzyme lactase, leading to digestive issues.
101
Why are saturated fats linked to heart disease?
They can raise LDL cholesterol levels, leading to atherosclerosis. ## Footnote High levels of LDL cholesterol contribute to the buildup of plaques in arteries, increasing heart disease risk.
102
Explain how a single amino acid substitution causes sickle-cell anemia.
It alters hemoglobin structure, leading to distorted red blood cells. ## Footnote The substitution of valine for glutamic acid in hemoglobin causes the cells to sickle under low oxygen conditions.
103
Which virus uses RNA as its genetic material?
HIV. ## Footnote HIV (Human Immunodeficiency Virus) is a retrovirus that uses RNA to replicate within host cells.
104
Why does ATP need to be regenerated constantly in muscle cells?
ATP is rapidly consumed during muscle contraction and needs replenishing for continued energy supply. ## Footnote Muscle cells rely on ATP for various functions, including contraction and relaxation, necessitating constant regeneration.
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