Chapter 2 Flashcards

1
Q

What is the most common solvent in solutions in the body?

A

Water

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2
Q

What is meant by a 10% NaCl solution? What are solute and solvent? What kinds of pressure do they exert?

A

10% NaCl
90% water

Solute: anything that is solid (ions, glucose, protein)
Solvent: water

When we have solute in the cell, it exerts osmotic pressure. The pressure sucks in water into the cell. The water outside the cell exerts hydrostatic pressure and pushes water into the cell.
[both direct water into the cell]

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3
Q

What type of bonds are found in a water molecule present between them?

A

Hydrogen bonds: between electropositive hydrogen molecule and electronegative atom of another molecule
(can be between negative O or some DNA & proteins)

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4
Q

What is a polar molecule? (2)

A

-Unequal sharing of electrons in a covalently bonded molecule
Ex. O more electronegative than H in H2O so O becomes slightly negative and H positive

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5
Q

6 Properties of Water

A
  • polar solvent properties. dissolves solutes. Body’s major transport medium
  • high heat capacity. absorbs and releases heat without major changes in temperature
  • high heat of vaporization, useful for cooling
  • reactivity: necessary for hydrolysis (catabolism) and dehydration synthesis (anabolism)
  • cushioning: protects certain organs from physical trauma (ex cerebrospinal fluid)
  • unique properties due to surface tension formed by H bonds (ex. water strider can walk on pond because high surface tension of water)
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6
Q

Define: Electrolyte, Acid, Base, Cation, Anion, Buffer

A
  • Electrolyte: ions that conduct electrical currents in a solution
  • Acid: proton donors, release H+
  • Base: proton acceptors, accepts H+ and makes H2O (bicarbonate ion HCO3- an important base in body)
  • Cation: positively charged molecule, lost electrons
  • Anion: negatively charged molecule, gained electrons
  • Buffer: compounds that resist change in pH
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7
Q

Explain the pH scale. Each number represents a “jump” of how many hydrogen ions?

A
  • pH is the concentration of H+ in a solution
  • logarithmic scale of 0 to 14
  • pH of water neutral (7) with equal numbers of H+ and OH- in solution
  • 0-6.99 acidic, 7.01-14 basic

10 times more H+ ions

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8
Q

A substance with a pH of 4 is how much more acidic than a substance with a pH of 7?

A

1000

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9
Q

Characteristics of carbohydrates (5)

A
  • contain C, H, O in 1:2:1 ration
  • sugars and starches
  • a source of fuel
  • structural moelcule
  • hydrophilic
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10
Q
Define the following carbohydrates:
monosaccharide
disaccharide
polysaccharide
Examples?
A

Monosaccharides: simple sugars, single-chain or single-ring structures
-Glucose, Fructose, Galactose, Deoxyribose, ribose

Disaccharides: 2 monosachs
-Sucrose (G+F), Maltose (G+G), Lactose (G+Galactose)

Poly: polymers of monosachs
-Glycogen, starch

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11
Q

What are the monomers of CHO, protein, and DNA?

A

glucose, amino acid, and nucleotides

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12
Q

Which is the smallest unit of a carbohydrate? Of a protein?

A

glucose, amino acid

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13
Q

Give 3 examples of the different types of fats and where they might be found in the body.

A

Neutral fats/triglycerides: 3 fatty acid chains bonded to glycerol. functions are protection, storage, and insulation

  • saturated FA: single bonds, max number of H, solid animal fats such as butter
  • unsaturated FA: double bonds, reduced number of H, plant oils such as olive oil

Phospholipids

  • glycerol + phosphate head (hydrophilic) + 2 fatty acid tails (hydrophobic)
  • membrane
Steroids
-cholesterol: HDL good, LDL bad
-vitamin D
-steroid hormones
Ex. lipoproteins transport fats in the blood,  prostaglandins released when in pain
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14
Q

How many different amino acids are there and what elements do they contain?
What do each amino acid consist of?

A

-20
C, H, N, O, sometimes S, P
-amino group, carboxyl group, R group

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15
Q

What is a peptide bond?

A

bond between amino acids

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16
Q

What are the 4 structural levels of proteins

A
  1. amino acids in a polypeptide chain
  2. alpha-helix and B sheet
  3. tertiary structure: alpha helix or beta-sheets folded up (most proteins become functional at this stage)
  4. quaternary structures: 2 or more polypeptide chains (ex. hemoglobin active at this structure)
17
Q

Essay question. Give the name, type of protein, location, and function of 3 proteins

A
  1. Actin is a fibrous, contractile protein that is found in the muscle. Its function is to make the muscle contract.
  2. Hemoglobin is a globular, transport protein that is found in the blood. Its function is to transport O2, CO2, nutrients, and wastes.
  3. Insulin is a globular, hormone protein that is produced by the pancreas. Its function is to decrease blood glucose level.
18
Q

What are the 8 functions of proteins?

A
  1. Enzymes: lower activation energy and speed up the rate of reaction
  2. structural: make up cell membranes, bones, muscles, ligaments, tendons, hair, nails, & skin
  3. transport: carry O2 in RBC, pump nutrients and ions across membranes
  4. hormonal: regulate homeostasis
  5. defensive: antibodies
  6. contractile: movement
  7. receptor: membrane-bound & receive chemical signals
  8. energy: don’t want this! degenerates muscle
19
Q

What happens when a protein is irreversibly denatured? Explain in terms of its structure.

A

-H bonds broken, 3D shape changes, disruption of active sites permanently

20
Q

What causes the denaturation of a protein?

A

heat, pH

21
Q

What is the difference in fibrous and globular proteins? What are examples?

A
  • globular round in structure, fibrous elongated
  • fibrous insoluble in water, globular soluble in water

Fibrous:

  • contractile proteins (actin & myosin)
  • structural proteins (keratin, elastin, collagen)

Globular proteins:

  • also called functional proteins
  • enzymes (lactase), transport (hemoglobin), hormones (insulin), antibodies
22
Q

Give some characteristics of enzymes. (7) What type of molecule are they? (carb, protein, lipid??)

A

Characteristics:

  • not used up in reactions
  • contains active sites where substrate binds
  • changes substrates into products
  • end in ase
  • need a cofactor (Zn, Cu) or a coenzyme (vitamin B12)
  • chemically specific
  • some produced in an inactive form and must be activated

Proteins

23
Q

What is a substrate? A product?

A
  • substrate: anything enzymes acts on

- product: the substances produced

24
Q

What makes up a nucleotide? (3)

A

N-containing base, pentose sugar, phosphate group

25
Q

What are the 2 major classes of nucleic acids? (3, 4)

A

DNA & RNA (they are the largest molecule in the body!)

DNA

  • double-stranded helix
  • in nucleus
  • carries genetic code & protein synthesis instructions

RNA

  • single-stranded
  • in cytoplasm
  • translates into proteins
  • 3 varieties: messenger RNA, ribosomal RNA, transfer RNA
26
Q

What 4 nitrogen bases are found in DNA? In RNA? How do they pair?

A
  • thymine, guanine, cytosine, adenine
  • uracil, guanine, cytosine, adenine

CG
AT or AU

27
Q

What is the role of DNA in the body? Of RNA?

A
  • DNA: carry genetic code for proteins

- RNA: translate the proteins

28
Q

Describe ATP—its role in the body, its makeup, and how energy is released.

A

-adenine containing RNA nucleotide with 3 phosphate groups
-function: energize other molecules (phosphorylation) for cellular work
-the 3rd phosphate bond has most energy, then the 2nd
AMP: adenosie monophosphate
ADP: adenosine diphosphate
ATP: adenosine triphosphate

29
Q

How many valence electrons are in the first and second shell? How many do elements want? What is special about inert gases?

A
  • 2 in first shell, 8 in second shell
  • elements want 8
  • inert gases have 8 so want 8
30
Q

What are ionic bonds? What happens to the charges of an element when they lose or gain an electron? What do they form? What is an example of an ionic bond?

A
  • transfer of valence shell electrons
  • anions have - charge (gained e)
  • cations have + charge (lost e)
  • ionic compounds form crystals
  • salt
31
Q

What are covalent bonds? What are the 2 types and its examples?

A
  • sharing of electrons in the valence shells
  • unequal: polar, ex H2O
  • equal: nonpolar, ex CO2
32
Q

What bonds are in between atoms within a water molecule and between neighboring water molecules?

A

covalent, hydrogen bonds

33
Q

Difference between inorganic and organic compounds (3) What are some examples? (4)

A

Inorganic

  • no C
  • except CO & CO2 considered inorganic
    ex. water, salts, acids, bases

Organic

  • contain C, usually large, and covalently bonded
  • carbs, fats, proteins, nucliec acids
34
Q

What are salts? (2) What are the 4 most important ones in the body?

A
  • ionic compounds that dissociate in water
  • conduct electrical current
  • esp important ones in body are Na, K, Ca, Iron
35
Q

Catabolic and Anabolic reactions involve…

A
  • dehydration synthesis (make H2O)

- hydrolysis (use H2O)

36
Q

What is the central dogma of biology?

A

DNA > RNA > Protein
Nucleus > cytoplasm > ribosome
replication > transcription > translation

37
Q

amino acids are also called

A

peptide