Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cell Biology > Ch 2: Chemical Components of Cells > Flashcards

Ch 2: Chemical Components of Cells Flashcards

1
Q

What are the primary four elements that make up a cell’s mass?

A

C, H, N, O make up 96% of a cell’s mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What determines the atomic number of an atom?

A

The number of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the most abundant molecule in a cell?

A

Later makes up 70% of a cell’s mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the main categories of molecules that make up a cell?

A

1) sugars
2) fatty acids
3) amino acids
4) nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sugars overview

A

Primary source of chemical energy for cells

Join together to form polysaccharides or shorter oligosacchardes

Important for central metabolism in all organisms–we share the same process with everything, bacteria included

In water sugars tend to form into rings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Fatty acid overview

A

Rich energy source by primary role is to form lipids that assemble into cell membranes
Consists of a carboxylic acid (-COOH) (hydrophilic) attached to a long hydrocarbon chain (hydrophobic)
Starting point for the synthesis of phospholipids
When the hydrocarbon chain is missing and hydrogen and has a double-bond, the tail kinks and it is called unsaturated, and doesn’t pack as well together (more liquid at room temp)
When the hydrocarbon tail is full of hydrogen atoms and no double bonds the tails are straight and pack together well and are more likely to be solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Macromolecules

A

The majority of the dry mass of a cell
Polymer molecule formed from covalently linked subunits of polysaccharides, proteins, and nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Protein overview

A

Formed from 20 different types of amino acids covalently joined by peptide bonds into long polypeptide chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nucleotides overview

A

DNA, RNA, and energy-transfer reactions in cells
A nucleoside linked to a phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How protein, DNA, and RNA are synthesized

A

Chained together from subunits by repetitive condensation reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Types of weak, non-covalent interactions in cells

A

1) hydrogen bonds
2) electrostatic attractions
3) van der Waals attractions
4) hydrophobic force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Acid

A

A molecule that releases a proton when dissolved in water
This generates hydronium ions (H3O +)
Lowers the ph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Amino acid

A

Contains:
- an amino group
- a carboxyl group
- an alpha-carbon
- a side chain
Serves as the building block of proteins
Life uses 20 amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ATP

A

Activated carrier that is the main carrier of energy in cells
Nucleoside triphosphate composed of adenine, ribose, and three phosphate groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Avogadro’s number

A

The number of molecules in a mole: 6x10^23
The quantity of a substance equal to its molecular weight in grams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Base

A

Molecule that accepts a proton when dissolved in water, creating OH- by removing the proton from water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Buffer

A

Mixture of weak acids and bases that maintains the ph of a solution by releasing and taking up protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Chemical group

A

a combination of atoms such as a hydroxyl group (-OH) or an amino group (-NH2) with distinct chemical and physical properties that influences the behavior of the molecule in which it resides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

condensation reaction

A

covalent bond that happens between two molecules that expels a water atom.
Used to build polymers such as proteins, polysaccharides, and nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

electronegativity

A

the tendency of an atom to attract electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Electrostatic Attraction

A

force the draws together oppositely charged atoms (ex ionic bonds and the attractions between molecules containing polar covalent bonds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Hydrogen bond

A

weak non-covalent interaction between a positively charged hydrogen atom in one molecule and a negatively charged atom (such as oxygen or nitrogen) in another.
Key to the structure and properties of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Hydrolysis

A

reaction that cleaves a covalent bond and consumes a water molecule–adds on -H to one end and an -OH to the other end
The reverse of a condensation reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

hydronium ion

A

the form taken by a proton (H+) in an aqueous solution (H3O+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Hydrophobic force

A

non covalent interaction that forces together the hydrophobic portiosn of dissolved molecules to minimize the disruption of the hydrogen-bonded network of water
causes phospholipids to form into a bilayer
helps proteins fold into compact, globular shapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Ionic Bond

A

when one atom donates an electron to another. Both atoms become electrically charged

Atoms held together by ionic bonds are typically called salts rather than molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Lipid

A

organic molecule that is insoluble in water
typically long hydrocarbon chains or multiple rings
phospholipid is one class of lipid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Monomer

A

small molecule that can be linked to others of a similar type to form a larger molecule (polymer)

29
Q

Polymer

A

Long molecule made by covalently linking multiple identical or similar subunits (monomers)

30
Q

Protein

A

Macromolecule built from amino acids that provides cells with their shape and structure and performs most of their activities

31
Q

RNA

A

Ribonucleic acid
Molecule produced by the transcription of DNA, usually single-stranded, a polynucleotide composed of covalently linked ribonucleotide subunits.
Performs informational, structures, catalytic, and regulatory functions in cells

32
Q

van der Waals attraction

A

weak non-covalent interaction, due to fluctuating electrical charges that come into play between two atoms located very close to each other
Can happen even between non-polar molecules

33
Q

Why does Carbon play a unique role in the cell?

A

It’s ability to form strong covalent bonds with other carbon atoms
Just about all carbon molecules form four bonds. If there is a diagram with some missing, assume there are hydrogen atoms there that just aren’t shown

Carbon skeletons can form into chains, branched trees, and rings

34
Q

Hydrocarbons

A

C-H compounds or groups made of carbon and hydrogen
non-polar, so do not form polar bonds and are insoluble in water
ex: methane, methyl group

35
Q

CO compounds

A

-OH hydroxyl
C=O carbonyl
-COOH carboxyl (loses an H+ in water to become -COO-

36
Q

Blank

A

Amines in water combine with H+ to become positively charged
Amide formed by an acid and an amine, uncharged in water
Nitrogen also forms into ring compounds such as purines and pyrimidines, which are important parts of nucleic acids

37
Q

Formula/Structure of an amino acid

A

1) alpha carbon atom
2) amino group
3) carboxyl group
4) side chain

38
Q

Phosphates in nucleotides

A

normally joined to the C-5 hydroxyl of the ribose or deoxyribose sugar
can be mono, di, or tri
Makes the nucleotide negatively charged

39
Q

Nucleotide structure

A

a nitrogen-containing base, a five-carbon sugar (pentose), and one phosphate group

40
Q

Nucleic Acids

A

nucleotides joined by phsophodiester bonds between the 5’ and 3’ carbon atoms of adjacent sugar rings
formed by adding onto the 3’ end
Formed from:
1) base
2) phosphates
3) 5-carbon sugar (ribonucleic acid or deoxyribonucleic acid)

41
Q

Phospholipid

A

Makes the phospholipid bilayer
Hydrophilic head:
a) polar group
b) phosphate
c) glycerol
Two hydrophobic fatty acid tails

42
Q

Bond strength

A

Different bonds have a different strength (different energy needed to break the bond)

43
Q

Polypeptide chain

A

four atoms in each peptide bond
starts at N terminus of polypeptide chain and the next attachment is at the C terminus

44
Q

Nucleotide base

A

nitrogen-containing ring compounds, either pyrimidine (cytosine, thymine, uracil) or purine (adenine, guanine)

45
Q

Other functions of nucleotides besides RNA and DNA

A

ATP: chemical energy
Co-A combine with other groups to form enzymes
cAMP: signaling molecule

46
Q

Two general chemical rules

A

Opposite charges attract (electrostatics–enthalpy)
oil and water don’t mix (hydrophobic forces–entropy)

47
Q

Energy and Catalysis

A

Catabolic pathways: break food down into:
- useful forms of energy
- lost heat
- many building blocks for biosynthesis
Anabolic pathways: take energy and building blocks and turn them into the molecules that form cells

48
Q

Free Energy change

A

determines whether a reaction can happen spontaneously
- there is an activation barrier to the reaction
- enzymes lower the activation energy for a catalyzed reaction

Free energy determines the relative amounts of starting paterial and product (delta G)

-catalysts don’t change the final concentration, only how quickly the changes can happen

  • sequential changes add delta G values, and allow a favorable reaction to drive an unfavorable one
49
Q

Activated carrier molecule

A

Holds onto energy in the form of chemical bonds
Most common one is ATP

50
Q

Protein Synthesis

A

Goes from N-terminus of polypeptide chain to C-terminus of polypeptide chain

Linked by peptide bonds

51
Q

Blank

A

1) Uncharged polar side chains
2) Non-polar side chains
3)

52
Q

How is biological order made possible?

A

The release of heat energy from cells increases entropy as the cells create order

53
Q

What is the sugar group that is found in RNA?

A

ribose sugar, in contrast to the deoxyribose sugar found in DNA. Ribose sugar has 1 more hydroxyl group on 2’ carbon than deoxyribose sugar.

54
Q

In addition to the DNA and genome, what other important biological molecules are nucleotides part of?

A

ATP

55
Q

What kind of molecule does this picture represent? What are the different components called?

A

Phospholipid
from the bottom up:
- fatty acid chain
- glycerol
- phosphate group
- polar head group

56
Q

What kind of molecule is this? Name all parts on the molecule

A

Amino acid molecule
Left–>right: amino group, alpha carbon, side chain, and carboxylic acid group.

57
Q

What part of the molecule is charged?

A

the phosphate group is negatively charged

58
Q

What direction does DNA synthesize from?
What direction does protein synthesize from?

A

DNA: 5’ to 3’
Protein: N-terminus to C-terminus

59
Q

Explain what catalysts do in terms of energy diagram
Do catalysts change the delta G of the reaction?

A

Catalysts lower the activation energy of a reaction, and do not change the delta G of a reaction

60
Q

What is the second law of thermodynamics and how to organized life forms deal with the second law?

A

A system always moves towards greater entropy. Life forms deal with this by releasing heat during their reactions

61
Q

Nucleoside

A

a base plus its sugar with no phosphate group attached

62
Q

Why can scientists substitute radioisotopes for isotopes commonly found in cells when conducting experiments?

A

Radioisotopes of an element differ only in the number of neutrons, so they behave the same way chemically as the isotopes that occur in cells

63
Q

Which subatomic particle is found in the nucleus of a hydrogen atom?

A

A proton only (no neutrons, and only one electron)

64
Q

The atomic weight of an atom is its mass relative to what?

A

hydrogen. The atomic mass of an atom or molecule is specified in daltons, one dalton is equal to the mass of a hydrogen atom.

65
Q

On the basis of mass, what type of molecule is the most abundant in a living bacterial cell?

A

Water. All cells are about 70% water by weight

66
Q

Covalent bonds are formed by the sharing of electrons. In the cell, how are covalent bonds broken?

A

Enzyme catalysis that is specific for a protein and its substrate

67
Q

Which of the following would most likely interact by forming an ionic bond?

A

ATP and magnesium cations (ATP is negatively charged)

68
Q

How do protein, nucleic acid, and polysaccharide molecules polymerize (grow in length)

A

By condensation reactions. A molecule of water is lost with the addition of each monomer to to the growing polymer chain.

69
Q
A

Cell Biology (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions