Campbell Biology Concepts And Connections Chapters 10-11, 13-15, And 31-21

Front 1

Molecular biology

Back 1

The study of the heredity at the molecular level.

Front 2

What did scientists first think was the basis for hereditary material, and why?

Back 2

Scientists first thought proteins were the basis for genetic material, as proteins are more complex, having 20 different amino acid building blocks compared to DNA's 4.

Front 3

Who first discovered DNA's genetic role, and who found the first convincing evidence for it?

Back 3

DNA's genetic role was first discovered in 1928 by Frederick Griffith, while scientists Hershey and Martha Chase conducted the experiment that confirmed Griffith's findings.

Front 4

Bacteriophages (phages for short)

Back 4

Viruses that exclusively infect bacteria.

Front 5

What convinced Hershey and Chase that DNA, rather than protein, is the genetic material of phage T2?

Back 5

Radioactively labeled phage DNA, but not labeled protein, entered the host cell during infection and directed the synthesis of new viruses.

Front 6

Nucleotides

Back 6

The monomers for DNA and RNA

Front 7

Polynucleotide

Back 7

A nucleotide polymer

Front 8

Sugar-phosphate backbone

Back 8

A sugar molecule connected to a phosphate group, which is in turn connected to another sugar, ect.

Front 9

Deoxyribonucleic acid

Back 9

The full name for DNA.

Front 10

Pyrimidines

Back 10

Nucleotides that are single-ring structures. Pyrimidines consist of thymine (T) and cytosine (C).

Front 11

Purines

Back 11

Nucleotides that are double-ring structures. Purines consist of adenine (A) and guanine (G).

Front 12

What are the three main differences between DNA and RNA?

Back 12

1. DNA=Deoxyribose, RNA=Ribose

2. DNA=ATGC, RNA=AUGC

3. DNA=Double-stranded, RNA=Single-stranded

Front 13

DNA helicase?

Back 13

An enzyme that unzips your genes, if you know what I mean ( ͡° ͜ʖ ͡°) ( ͡° ͜ʖ ͡°)

Front 14

What is multiple replication and what is it's purpose?

Back 14

DNA Helicase unzips in opposite directions, forming "replication bubbles." This allows for faster replication.

Front 15

RNA Primase

Back 15

An enzyme that drops RNA code onto a single DNA strand to identify the replication start point.

Front 16

DNA Polymerase III

Back 16

An enzyme that adds nucleotides, starting at the RNA start point, in a 5'--->3' direction.

Front 17

DNA Polymerase I

Back 17

An enzyme that replaces RNA nucleotides with DNA nucleotides.

Front 18

DNA Ligase

Back 18

An enzyme that fuses Okazaki fragments.

Front 19

Semiconservative model

Back 19

When DNA replicates, the daughter molecules will consist of one old DNA strand and one new one.

Front 20

Transcription

Back 20

The synthesis of RNA under the direction of DNA.

Front 21

Translation

Back 21

The synthesis of protein under the direction of RNA.

Front 22

Triplet code

Back 22

Three nucleotides in a sequence code for one amino acid.

Front 23

Codon

Back 23

A three base "word" in DNA and RNA that codes for one amino acid.

Front 24

Promoter

Back 24

The "start transcribing" signal in DNA.

Front 25

Terminator

Back 25

The sequence of bases in DNA that tells RNA polymerase to stop transcribing and detach from DNA, leading to a completed RNA gene ready for translation.

Front 26

RNA Polymerase

Back 26

The enzyme that transcribes DNA and creates a corresponding RNA molecule.

Front 27

mRNA

Back 27

A type of RNA that conveys genetic information from DNA to the translation machinery of the cell. It is created in transcription.

Front 28

Introns

Back 28

Segments of mRNA that are removed before translation.

Front 29

Exons

Back 29

Segments of mRNA that are kept and spliced together during translation.

Front 30

tRNA

Back 30

A type of RNA that translates the words of nucleic acids to the amino acid words of proteins.

Front 31

Anticodon

Back 31

A base triplet of a tRNA molecule that couples the tRNA to a complementary codon in the mRNA.

Front 32

Ribosomes

Back 32

Structures in the cytoplasm that position mRNA and tRNA close together and catalyze the synthesis of polypeptides.

Front 33

rRNA

Back 33

A type of RNA that combines with proteins to make a ribosome.

Front 34

P site

Back 34

Site that holds the growing polypeptide chain.

Front 35

A site

Back 35

Site that accepts a new tRNA molecule with the appropriate amino acid attached.

Front 36

Codon recognition

Back 36

The first step in elongation. The anticodon of an incoming tRNA molecule, carrying it's amino acid, pairs with the mRNA codon in the A site of the ribosome.

Front 37

Peptide bond formation

Back 37

The second step in elongation. The polypeptide separates from the P site and attaches to the amino acid in the A site.

Front 38

Translocation

Back 38

The third and final step in elongation. The P site tRNA leaves the ribosome, and the ribosome moves the remaining tRNA to the P site. The anticodon and anti-codon remain bonded, so the mRNA and tRNA move as a single unit.

Front 39

Initiation

Back 39

The first part of translation. The initiator tRNA bonds to the start codon, starting the amino acid chain.

Front 40

Termination

Back 40

The final step in Translation. When the stop codon reaches the ribosome's A site, the polypeptide is freed from the last tRNA, and the ribosome splits back into it's separate subunits.

Front 41

Silent mutation

Back 41

When a substitution mutation changes a codon, but the new codon still codes for the same protein.

Front 42

Missense mutation

Back 42

When a substitution mutation changes a codon, and the new codon now codes for a different protein.

Front 43

Nonsense mutation

Back 43

When a substitution mutation change an amino acid codon into a stop codon, making the protein terminate prematurely, screwing everything up!

Front 44

Reading frame

Back 44

The triplet groupings of the message. Any time a nucleotide deletion or insertion occurs, the reading frames of the mRNA downstream will be altered.

Front 45

Insertion mutation

Back 45

When a nucleotide is added to the mRNA, altering the reading frame of everything "downstream" of the message.

Front 46

Deletion mutation

Back 46

When a nucleotide is removed from the mRNA, altering the reading frame of everything "downstream" of the message.

Front 47

Mutagenesis

Back 47

The production of mutations. Spontaneous mutagenesis is often the result of errors during DNA replication or recombination. Other times, mutagenesis is caused by physical or chemical agents, known as mutagens.

Front 48

Mutagens

Back 48

Physical or chemical agents that cause mutations.

Front 49

Virus

Back 49

A virus is pretty much just "genes in a box:" an infectious particle consisting of a bit of nucleic acid wrapped in a protein coat called a capsid and, inn some cases, a membrane envelope.

Front 50

Capsid

Back 50

A protein coat that holds the nucleic acid in a virus.

Front 51

Lytic cycle

Back 51

When a phage inserts it's DNA into a cell, phage DNA and proteins are synthesized inside of it, assemble, and break out, destroying the cell.

Front 52

Lysogenic cycle

Back 52

When a phage inserts it's DNA into a cell, and the phage DNA inserts into the cell's DNA. The cell replicates, duplicating the phage's DNA. Often, this virus will lurk inside cells for a long time before causing damage.

Front 53

Emerging viruses

Back 53

Viruses that appear suddenly or are new to medical scientists

Front 54

What are three ways that emerging viruses appear?

Back 54

Mutation, contact between species, and spread from isolated populations.

Front 55

Reverse transcriptase

Back 55

An enzyme carried by HIV that catalyzes reverse transcription, the flow of genetic information backward from RNA to DNA.

Front 56

Retroviruses

Back 56

Viruses that use reverse transcription to make DNA that inserts itself into the chromosomal DNA, which in turn creates more virus RNA that spreads the virus.

Front 57

Viroids

Back 57

Small circular RNA molecules that infect plants. They don't encode proteins, instead using cellular enzymes to replicate. They cause errors in regulatory systems that control plant growth.

Front 58

Prions

Back 58

Small infectious proteins that cause degenerative brain diseases in animals. They are misfolded forms of proteins present in brain cells, and converts other forms of the protein to misfolded versions, causing the brain to clump and leading to loss of brain tissue. Remember, they have no nucleic acid!

Front 59

What are the three ways that bacteria can transfer DNA?

Back 59

Transformation (the uptake of foreign DNA from the surrounding environment), transduction (the insertion of DNA into a bacteria cell by a bacteriophage), and conjugation (the physical union of two bacteria and the subsequent transfer of DNA from the Donor cell to the Recipient cell).

Front 60

Transformation

Back 60

One way bacteria transfer DNA. Foreign DNA fragments enter the cell, and join with the bacterial chromosome.

Front 61

Transduction

Back 61

One way bacteria transfer DNA. During a lytic infection, a fragment of DNA is mistakenly placed in a phage's coat instead of the phage's DNA. When the phage infects a new bacterial cell, the DNA stowaway from the former host cell is injected into the new host.

Front 62

Conjugation

Back 62

One way bacteria transfer DNA. Two bacteria cells, the donor cell and the recipient cell, are physically joined by the sex pili, hollow appendages that belong to the donor cell. The outside layers of the cell fuse, forming a "mating bridge" that the donor cell's DNA passes through. As the donor cell transfers it's DNA, it also replicates it, so it doesn't lose any genes.

Front 63

F factor

Back 63

A specific piece of DNA that caries genes for making sex pili and other requirements for conjugation. Essentially determine's the bacteria's ability to mate.

Front 64

Plasmid

Back 64

A small, circular DNA molecule separate from the bacterial chromosome. Contain's the bacteria's F factor, genes that determine it's ability to conjugate (mate with other bacteria).

Front 65

R plasmids

Back 65

Plasmids that cary genes for enzymes that destroy antibiotics.

Front 66

Gene regulation

Back 66

The turning on and off of genes in response to environmental changes.

Front 67

Gene expression

Back 67

The process by which genetic information flows from genes to proteins.

Front 68

Operator

Back 68

A section of DNA in between the promoter and specific genes. When a repressor is active (in the case of lactose digestion, this occurs when no lactose binds to it), it binds to the promotor and prevents the RNA polymerase from binding to the promotor, thus blocking it from transcribing the genes.

Front 69

In the lac operon, when is the repressor active?

Back 69

When lactose is NOT bound to it.

Front 70

In the trp operon, when is the repressor active?

Back 70

When Tryptophan IS bound to it.

Front 71

Activators

Back 71

A type of operon that is the opposite of a repressor. It binds to the DNA to make it easier for RNA polymerase to bind to the promotor, instead of blocking the RNA polymerase.

Front 72

Differentiation

Back 72

A process that cells undergo to become specialized in structure and function. Caused by gene regulation varying between cells.

Front 73

DNA packing

Back 73

The wrapping of DNA in tight or loose areas to make it easier or harder for RNA polymerase to access the DNA, thus controlling gene expression.

Front 74

Histones

Back 74

Little protein balls that DNA wraps around

Front 75

Nucleosome

Back 75

Eight histones that form a square, that DNA wraps around

Front 76

Chemical modification

Back 76

A method of gene regulation, in which enzymes at a methyl group to DNA bases, deactivating them. Once a gene is methylated, it usually stays that way; in fact, methylated genes can be inherited in a process called epigenetic inheritance.

Front 77

X chromosone inactivation

Back 77

In a female mammal, one of their two X chromosomes is deactivated, and is condensed into a compact object called a Barr body. This leads to a phenom

Front 78

Barr body

Back 78

A deactivated, compacted X chromosome in a female.