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BIOS 222 with Kay and Wherpa > Chapter 2 > Flashcards

Flashcards in Chapter 2 Deck (84)
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1
Q

Name the most common biological atoms?

A
CHNOPS
Carbon 
Hydrogen 
Nitrogen
Oxygen 
Phosphorus 
Sulfur
2
Q

How many covalent bonds can atoms form?

A

8 minus the number of electrons in the outmost shell of the atom.

3
Q

What are some characteristics of double bonds?

A

They are more rigid and less flexible than single bonds. Single bonds allow for rotation.

4
Q

What is a polar structure?

A

A polar structure in one in which positive charge is concentrated at one end and negative charge is concentrated at the other. Leading to a negative and a positive pole.

5
Q

What are the two most electrically negative biological atoms?

A

Oxygen and nitrogen

6
Q

What biological atoms have a relatively weak electronegative charge?

A

Hydrogen

7
Q

Name a common biological bond that is relatively non-polar?

A

C-H

8
Q

Name two common biological bonds that are relatively polar?

A

O-H

N-H

9
Q

What makes a bond polar?

A

When the electrons are not shared equally in a covalent bond.

10
Q

How is bond strength measured?

A

the amount of energy required to break the bond. this is measured in kilocalories per mole (kcal/mol) or kilojoules per mole (kj/mole)

11
Q

What is stronger, ionic or covalent bonds?

A

When water is present covalent bonds are much stronger.

12
Q

What are salts?

A

Ions that held together only by ionic bonds

13
Q

How does water dissolve?

A

The electronegativeity of the O is stronger the the ionic bond of the NaCl, so it dissociates it into Na+ions and Ca- ions, which are surrounded by water.

14
Q

What holds water molecules together?

A

Weak hydrogen bonds between the positive and negative sections of two different molecules.

15
Q

Why are hydrogen bonds significant?

A

Without them life on earth would not exist. They are responsible for water’s surface tension. Water’s surface tension means that it has a high specific heat (boiling point) is liquid (not gas) at room temperature.

16
Q

What type of bonds are hydrogen bonds?

A

non-covalent

17
Q

What dissolves readily in water?

A

Anything with a positive or negative charge. These molecules are hydrophilic.

18
Q

Where do hydrogen bonds form?

A

Between anything with a polar covalent linkage what hold a hydrogen with a positive charge when it comes in contact with something with a negative charge.

19
Q

What makes a molecules hydrophobic?

A

These molecules are uncharged, don’t form hydrogen bonds and thus do not dissolve in water.

20
Q

Are hydrocarbons hydrophilic or hydrophobic?

A

They are hydrophobic because the H-C bonds they are composed of are non-polar.

21
Q

What makes up the tails of the lipids?

A

Hydrocarbon (H-C) tails

22
Q

How are acids formed?

A

When a highly polar covalent bond between hydrogen and another atom dissolves in water, the hydrogen atom gives up its election almost entirely to the other atom, so that exists as a naked proton H+ and then bonds with water creating a hydronium ion (H3O+)

23
Q

Why is water the universal solvent?

A
  1. ) It is polar
  2. ) It cohesive
  3. ) It has a high specific heat
24
Q

What defines and acid?

A

Substances that release proton (H+ ions) when they are dissolved in water.

25
Q

Do hydronium ions move around water.

A

Yes, water molecules are continually exchanging hydronium ions hydroxyl ions. These ions then reform H2O.

26
Q

What are hydronium ions?

A

H3O+

27
Q

What are hydroxyl ions?

A

HO-

28
Q

What determines the pH of a solution?

A

The presence of H3O hydronium ions. The more there are the more acidic the solution, the the lower the pH.

29
Q

What is another way to refer to H3O molecules.

A

H+. Although H3O is more accurate, the long running convention is H+

30
Q

What makes an acid strong?

A

The more easily a substance gives up its protons, the stronger the acid.

31
Q

Are carboxyl groups (COOH) acidic or basic?

A

Acidic

32
Q

What are acids?

A

Substances that release positively charges hydrogen ions into solutions.

33
Q

What are bases?

A

Substances that accept positively charged hydrogen ions. because they are OH- and then the positively charged hydrogen ion attaches, it become H2O

34
Q

What happens when bases are put in water?

A

The OH- strips the H+ off of the hydronium ion to form H2O.

35
Q

What do acidic solutions have?

A

Lots of H+ or hydronium ions

36
Q

What do basic solutions have?

A

Lots of OH-

37
Q

What is the pH of cytosol?

A

7.2

38
Q

What is the pH in the lysosome?

A

4.2. Thus is it highly acidic and good for breaking things down.

39
Q

What are buffers?

A

They limit the changes in the pH of a solution. They weak acid and bases and can act as either as the surrounding solution becomes too basic or too acidic.

40
Q

Why are buffers important in biology?

A

They keep pH in an appropriate range so that cells can perform their function.

41
Q

Functionally, what are sugars?

A

They are both energy sources and the subunits of polysaccharides.

42
Q

What is an organic molecule?

A

Molecules that have carbon

43
Q

What is a chemical group?

A

Groups of atoms such as methyl (-CH3), hydroxyl (-OH), carboxyl (-COOH), carbonyl (-C=O), phosphoryl (-PO3^2-) and amino (-NH2) groups that occur repeatedly in organic molecules. They groups have groups of characteristics.

44
Q

How many vacancies are there in carbon’s outer shell?

A

four

45
Q

What are inorganic molecules?

A

Any molecules that don’t have carbon

46
Q

What is the formula for glucose?

A

C6H12O6

47
Q

What is the empirical formula for sugars?

A

CH2O

48
Q

What are isomers?

A

Sets of molecules with the same chemical formula but different structures.

49
Q

What is the difference between cohesion and adhesion?

A

cohesion is when a substance sticks to itself. Adhesion is when something sticks to something else.

50
Q

Do lipids have a single monomer from with they are built?

A

no

51
Q

What are the names of the bonds that link monosaccharides together to form larger carbohydrates?

A

glycosidic bonds

52
Q

How do monosaccharides become di-, tri-, tetra-, or poly- saccharides.

A

Through condensation reactions when the -OH of two monosaccharides are bonded leaving and O as their connection. 2 Hydrogen and another O are left over so that H2O is expelled in condensation reactions.

53
Q

What is a condensation reaction?

A

When water is the product of a reaction. Two -OH groups come together, bond the two molecules of which they are a part, leaving a larger macromolecule bonded together at and O and producing H2O as a byproduct.

Moreover, water is expelled as the bond is formed.

54
Q

What is a hydrolysis reaction?

A

It is the reverse of a condensation reaction. It is the use of water to break a part a bond. Instead of expelling water, water is consumed. An H and -OH are added back to the O that bonded two molecules, leaving both molecules with -OH groups.

Water is consumed in this reaction.

55
Q

In what type of reaction is water consumed?

In what type of reaction is water expelled?

A

Consumed–>hydrolysis

Expelled–>condensation

56
Q

What is starch?

A

How energy is stored in plant cells

57
Q

What is cellulose?

A

The structural sugars in plants

58
Q

What is glycogen?

A

How animal cells store a surplus of chemical energy

59
Q

What are lipids?

A

They are responsible for the formation of cell barriers.

60
Q

What lipids make up the bilayer membrane?

A

The phospholipids.

61
Q

What are phospholipids made of?

A

Long hydrocarbon tails with a polar group at the head.

62
Q

What does amphipathic mean?

A

When something contains hydrophilic and hydrophobic parts.

63
Q

What is a dehydration reaction?

A

Dehydration and condensation reactions are the same thing that the substance expelled is water.

64
Q

What are triglycerides?

A

They are fatty acid tails with a glycerol head.

65
Q

How do you identify a fatty acids?

A

C-H bonds

66
Q

What is glycerol?

A

An alcohol with 3 carbon, 3 OH and 5 hydrogens. It is the head of triacylglycerols.

67
Q

What is a saturated fat?

A

A fat that doesn’t contain double bonds. Since they don’t contain double bonds they can be packed in more tightly leading them to be solid at room temperature.

68
Q

What is a unsaturated fat?

A

A fat that contains double bonds. It cannot be packed a tightly because of the double bonds and therefore liquid at room temperature.

69
Q

How are fatty acids stored?

A

in the cytoplasm of cells in the form of fat droplets composed of triacylglycerol, which are three fatty acid tails joined together by a glycerol head by covalent bonds.

70
Q

What are triacylglycerols?

A

They are the way the energy is stored in animal fat, plants oils etc. When a plant needs energy, a fatty acid chain can be released from a triacylglycerol and broken down into two-carbon units. These two carbon units are identical to those derived from the breakdown of glucose.

71
Q

What is the difference between triacylglycerols and phospholipids.

A

Triacylglycerols have a glycerol head and three fatty acid tails. Phospholipids have two tails, a glycerol head, the third -OH group where the final tail would have gone links to a hydrophilic phosphate group which then links to a small hydrophilic compound such as choline.

Also, triacylcycerols are strong hydrophobic.

72
Q

What do steroids do?

A

To provide rigidity to membrane structure and hormonal signaling.

73
Q

What is the structure of steroids?

A

Ringed hydrocarbons

74
Q

What is the function of proteins?

A

To carry out cell activities

75
Q

What defines an amino acid?

A

There is a carbon atom with an amino group (H2N) on one side and carboxyl group (COOH) on the other. There is also a functional group link to the carbon.

76
Q

What type of bonds hold proteins together?

A

peptide bonds, which are formed by a type of condensation reaction. The amino (NH2) and the carboxyl (COOH) bond to create a N-H-C=O bond and an H20 is expelled.

77
Q

Where are peptide bonds formed?

A

Between hydroxyl and amino groups

78
Q

What determines the function of an amino acid?

A

the r-group

79
Q

What are the different properties amino acids can have?

A

polar, non-polar, charged, other.

80
Q

What links nucleic acids together?

A

Phosphodiester bonds.

81
Q

What are the two functions of nucleotides?

A

Storing energy (ATP) and storing genetic information

82
Q

What is the base of ATP and ADP?

A

Ribose

83
Q

Where do nucleotides connect?

A

The phosphate group of one attaches to the hydroxyl group of the next

84
Q

What are macromolecules?

A

Covalently linked monomers that have been turned into long chains of polymers. Between small organic molecules and organelles