Overview of Cells and Cell Research Flashcards
- the origin and evolution of cells - cells as experimental models - tools of cell biology (101 cards)
1
Q
What are some applications of cell and molecular biology?
A
Medicine, agriculture, biomedical engineering, and biotechnology
2
Q
What are the similarities and differences between modern day cells and the ancestors of our cells?
A
All cells have common fundamental properties that have been conserved through evolution. Lifestyles of these cells are more varied now however.
3
Q
What is the most notable difference between prokaryotic cells and eukaryotic cells?
A
Eukaryotes have nucleus where genetic material is kept. Genetic material in prokaryotes floats around in the cytoplasm.
4
Q
What is the size difference between prokaryotic cells and eukaryotic cells?
A
Prokaryotes are muhc smaller, at approximately 1 nm, where as eukaryotes are 10-100 nm.
5
Q
How many base pairs are found in the DNA of prokaryotes?
A
1 million - 5 million
6
Q
How many base pairs are found in the DNA of eukaryotes?
A
15 million - 5 billion
7
Q
What are the chromosomes of prokaryotic DNA like?
A
Single circular DNA molecule
8
Q
What are the chromosomes of eukaryotic DNA like?
A
Multiple linear DNA molecules
9
Q
When were cells thought to have first evolved?
A
3.8 billion years ago.
10
Q
Describe the evolutionary background of modern day cells
A
Cells all evolved from a single ancestry, life did not evolve separately several times.
11
Q
How were the first living cells have thought to have arisen?
A
Spontaneous formation of organic molecules provided the basic materials needed for survival of living cells
12
Q
How was the current prevailing theory to how life evolved proved? Who’s experiments led to this, and when?
A
Stanley Miller - 1950
Provided evidence for the primordial soup theory.
Showed that organic molecules could form spontaneously in conditions that we suspect existed in early earth oceans.
13
Q
According to Miller’s experiments, what was Earth’s atmosphere made up of?
A
Methane
Hydrogen
Ammonia
14
Q
What was one of the most important features the macromolecule that living organisms evolved from had to have had?
A
Ability to replicate itself!
15
Q
Who discovered that RNA can catalyze chemical reactions, and when?
A
Altman and Cech
1980s
16
Q
Can nucleic acids self replicate?
A
Yes
17
Q
What type of chemical reactions can RNA catalyze?
A
Polymerization of nucleotides
18
Q
What is the main function of nucleic acids?
A
The principal informational molecules of the cell
19
Q
List the 2 types of nucleic acids
A
Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA)
20
Q
What is the main purpose of DNA?
A
Informational storage.
The main genetic material
21
Q
List the many purposes of RNA?
A
Each type has a different purpose:
- carrying genetic information
- protein synthesis
- regulation of gene expression
- processing and transport of RNA and proteins
22
Q
What type of RNA carries genetic information?
A
Messenger RNA (mRNA)
23
Q
What is the path mRNA takes?
A
mRNA carries information from DNA to the ribosomes
24
Q
What types of RNA are involved in protein synthesis?
A
Ribosomal RNA (rRNA) Transfer RNA (tRNA)
25
Describe the structure of DNA and RNA
Polymers of nucleotides
26
Describe the structure of nucleotides
Purine bases and pyrimiidine bases linked to phosphorylated sugars
27
What are the purine bases?
Adenine
| Guanine
28
What are the pyrimidine bases?
Cytosine
Thymine
Uracil
29
What is the main difference between DNA and RNA structurally?
DNA has a thymine pyrimidine bases, and RNA has uracil instead.
30
What type of sugar is in DNA?
2'-deoxyribose
31
What type of sugar is in RNA?
Ribose
32
What is the difference between nucleotides and nucleosides?
-
33
What is polymerization?
A reaction that involves connecting multiple simple molecules (monomers) together to create a polymer
34
What bonds form nucleotids?
Phosphodiester bonds between the 5'phosphate of one nucleotide and the 3'hydroxyl of another
35
What is the difference between polymers and oligomers?
Polymers are macromolecules made up of a large number of monomers
and Oligomers are macromolecules made up of a small number of monomers
36
What are oligonucleotides?
Polymers with only a few nucleotides
37
Would DNA and RNA be classified as an oligonucleotides?
No, they are polynucleotides.
| They may contain thousands or millions of nucleotides
38
Describe the 'ends' of a polynucleotide chain
One end has a 5'phosphate group and signifies the start of the genetic information, and the other end is a 3'hydroxyl group that signifies the end.
39
What direction is genetic information synthesized?
In the 5' to 3' direction
40
What are the complimentary base pairs of DNA?
Guanine and Cytosine
| Adenine and Thymine
41
What are the complimentary base pairs of RNA?
Guanine and Cytosine
| Adenine and Uracil
42
What do the bases in genetic strands do?
The order of the bases represent the information being stored. It is a language that is read and used to create proteins by RNA.
43
How are base pairs joined together?
Hydrogen bonds
44
What benefits do base pairings have when replicating DNA?
Because every base has a complimentary base it HAS to be with, only one strand of the double helix is needed to synthesize a new complementary strand out of RNA.
This makes nucleic acids capable of self replication
45
What does the information carried by DNA and RNA do?
Directs synthesis of specific proteins, which control most cellular activities
46
What is ATR?
A nucleotide that is the principle form of chemical energy within cells
Adenosine 5'-triphosphate
47
What is AMP
A cyclical nucleotide that act as signals within cells
48
What is the most diverse type of macromolecule?
Proteins!
49
How many unique proteins are found in every cell?
Several thousand
50
What do proteins do?
Just about everything!
- structural components
- transport and storage of small molecules (ex. O2)
- transmit information between cells (protein hormones)
- defend against infection (antibodies)
- enzymes
51
What are proteins made out of?
Polymers of 20 different amino acids
52
What are amino acids made of?
An alpha carbon bonded to a carboxyl group (COO-), and amino group (NH3+), a hydrogen, and a side chain.
53
What are some characteristics that we categorize amino acids by?
- Nonpolar side chain
- Polar side chain
- Acidic side chains terminating in carboxyl groups
- Basic side chains
54
List the 10 nonpolar amino acids:
```
Glycine
Alanine
Valine
Leucine
Isoleucine
Proline
Cysteine
Methionine
Phenylalanine
Typtophan
```
55
List the 5 polar amino acids:
```
Serine
Threonine
Tyrosine
Asparagine
Glutamine
```
56
List the 3 basic amino acids:
Lysine
Arginine
Histidine
57
List the 2 acidic amino acids
Aspartic Acid
| Glutamic Acid
58
How are amino acids joined?
Peptide Bonds
59
What are polypeptides?
Chains of amino acids, can be hundreds or thousands of amino acids in length
60
Describe the different ends of a polypeptide
One end has an alpha amino group (N terminus)
| the other ends in an alpha carboxyl group (C terminus)
61
What determines the characteristics (form and function) of proteins?
The order of the amino acid sequence.
62
Who discovered the sequence for insulin and when?
Frederik Sanger
| 1953
63
How do we figure out protein sequences?
By analyzing the sequences of mRNA strands
64
How are proteins and genetic material connected?
The order of nucleotides of the gene determines the sequence of the amino acids in the protein
65
What is the physical structure of proteins like?
Unpredictable 3D knots of long amino acid sequences.
| Almost looks like spaghetti.
66
What causes the shape of proteins?
The types of amino acids that make up the protein and the interactions between them affect how the protein is folded
67
Is the physical structure of a protein important to it's function?
Yes, because the shape is determined by the amino acid sequence
68
Who figured out the importance of the 3D structure of proteins and how?
Christian Anfinsen
Disrupted proteins by treatments such as heating to break the noncovalent bonds.
This would change the shape of proteins
69
What is the term for breaking bonds in a protein to ruin its shape?
Denaturization
70
Are proteins that are denatured permanently ruined?
If the denaturization is mild, then no, it will go back to normal.
71
How do we analyze protein structure?
Through x-ray crystallography
72
How does x-ray crystallography work?
It is used to analyze crystal structured solids
It makes use of the natural spaces between molecules
Light is shined at the protein and the diffraction and wavelength of the photons are measured to determine what the arrangement of atoms in the molecule is.
73
Who first discovered the 3D structure of the protein myoblobin.
Describe the structure a bit and what it told us about proteins.
John Kendrew
153 Amino Acids
We learned some basic principles of protein folding
74
What are the 4 levels of protein structure?
Primary Structure
Secondary Structure
Tertiary Structure
Quaternary Structure
75
What is the primary structure of a protein?
The sequence of amino acids in the polypeptide chain
76
What is the secondary structure of a protein?
The arrangement of amino acids within localized regions. This determines the shape of small stretches of protein chain
77
What are the two most common types of secondary protein structure?
```
alpha helix (spiral)
beta sheet (flat and zigzag bent)
```
78
How are secondary structures held together?
With hydrogen bonds between the CO and NH groups of peptide bonds
79
What is the tertiary structure of a protein?
The chain folds that occur due to interactions between side chains of amino acids in different regions of the chain.
80
What is the domain of a protein?
A section of protein that is identifiable. Will often be associated with specific functions. These domains are a result of the tertiary structure.
81
How do hydrophobic and hydrophilic amino acids affect the shape of the tertiary structure?
Hydrophilic amino acids will fold around the hydrophobic amino acids, causing them to be on the inside of the wad of the structure. This is to attempt to protect the hydrophobic amino acids so that they do not come in contact with the cytoplasm, which is largely made of water.
82
What are loop regions of a tertiary structure?
Connect secondary structures together.
Usually these loops the area of proteins that are folded and polar amino acids form hydrogen bonds with water or other polar amino acids in the protein.
83
What is the Quaternary structure of a protein.
Composed of all of the tertiary structure sections to make up the entire protein.
The interactions between the different polypeptide chains.
84
What is hemoglobin made of?
4 polypeptide chains
85
What is one of the primary roles of proteins?
Enzymes!
86
What are enzymes?
Catalysists that increase the rate that a chemical reaction occurs.
Some reactions are so slow they wouldn't even occur, so enzymes allow those to happen
87
What are the fundamental properties of enzymes?
Increased rate of chemical reactions without the enzymes themselves being consumed
Increased reaction rates without altering the chemical equilibrium between reactants and products
88
What is a substrate?
The chemicals that are going to be converted into a product during a chemical reaction
89
How is the chemical reaction equilibrium affected by enzymes?
It isn't. The yield will be the same, you just get it faster
90
What is the transition state?
A higher state of energy that a substrate can reach to cause the reaction to occur faster
91
What is activation energy?
The amount of energy required for a chemical reaction to occur
92
What do enzymes do to the activation energy of a reaction?
Lowers it
93
What does lowering the activation energy of a reaction do?
It lowers the amount of energy required to fully complete the reaction. This is how it takes less time to finish the reaction
94
How do enzymes lower the activation energy?
They bind to the substrate to form an enzyme-substrate complex (ES)
The substrate binds to a specific region on the enzyme, the activation site.
While bound to the activation site, the substrate is converted to the product then released
95
What is the activation site
A cleft or groove on the surface of an enzyme that fits a specific type of substrate.
This groove is formed by the tertiary structure.
Substrate binding to the active site is a very specific interaction.
96
How do substrates bind to the activation site?
With hydrogen bonds, ionic bonds, and hydrophobic interactions
97
How many substrates bind to an enzyme to complete most biochemical reactions?
2 or more
98
How do 2 or more substrates fit into the activation site of an enzyme?
The enzyme brings the substrates together into the proper orientation to fit the groove.
This orientation will favour the transitional state
99
What are the two types of methods that enzymes accelerate reactions?
Lock-and-key model
| Induced fit model
100
Describe the lock-and-key model
The substrate fits perfectly into the active site
101
Describe the induced fit model
The conformation of the enzyme and substrate are modified to create an even tighter fit.
