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Microbiology > Exam 3 > Flashcards

Flashcards in Exam 3 Deck (55):
1

The function of a gene is...

To build proteins, carry genetic information, and to dictate the amino acid sequence and chain length of a protein

2

The entire DNA double helix is copied during...

DNA replication

3

A polypeptide is synthesized during...

Transcription

4

tRNA carries amino acids during...

Translation

5

mRNA is synthesized during...

Transcription

6

What happens to introns?

They are clipped out of mRNA before translation

7

How are DNA and RNA similar?

They are both involved in protein synthesis and are composed of nucleotides

8

The function of a prokaryotic flagellum is...

Motility

9

The function of pilus is...

Conjugation

10

The function of Fimbrea is...

Adhesion

11

Transcription begins when RNA polymerase binds fo the DNA at the...

Promoter

12

Flagellum

Structurally similar to cilia but fewer in number in a cell and longer

13

Leucoplast

Type of plant organelle that stores starch

14

Cytosol

Fluid membrane that bathes the contents of the cytoplasm

15

Golgi

Stacks of flattened membrane sacs which package molecules in vesicles for transport and secretion

16

Lysosomes

Membrane sacs that contain hydrolytic enzymes. Enzymes that assist in hydrolysis reactions.

17

Endoplasmic reticulum

Membranous canals that are found throughout the cytoplasm

18

Cell wall

Found outside the cell membrane

19

Ribosomes

Small granules which are present in both eukaryotic and prokaryotic cells which assist in protein synthesis from amino acids.

20

Nucleus

Structure composed of double membrane surrounding chromatin

21

Chloroplast

Organelle which carries out photosynthesis

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Vacuole

Membrane sac of fluid. Plants have a large one and animal cells have a small one

23

Mitochondrion

Organelle which carries out chemical reactions which allow oxidation of organic molecules and the use of that energy to produce ATP, the useful form of chemical energy for cells.

24

Cilia

Numerous short hair like structures which often assist a cell in moving.

25

Plasma membrane

Structure which regulates passage of molecules into and out of the cell.

26

Genetics

The study of how organisms inherit DNA, and how variations in DNA result in differences between people.

27

Genome

The complete set of genetic instructions for any organism

28

Gene

Short stretch of DNA in a genome that carries the information required to express a single polypeptide

29

Genotype

The precise sequence of nucleotides found in an organism that specify the genetic makeup of that individual

30

Phenotype

Observable physical properties of an individual

31

Transcription

The process of making an RNA copy of the DNA sequence of a specific gene sequence. The copy is mRNA

32

Translation

When the genetic information contained in the mRNA is used as a blueprint to make protein. mRNA is decoded during this process and used to make amino acids

33

mRNA

Messenger RNA is a copy of the DNA contained in a gene that transfers the genetic info from DNA inside the nucleus to the ribosomes in the cytoplasm

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rRNA

Ribosomal RNA is a type of RNA that makes ribosomes

35

tRNA

Transfer RNA delivers amino acids to the ribosomes

36

Anticodon

Three nucleotides that are a part of the amino acid that binds to the mRNA codon

37

Mutation

Permanent change in the DNA

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Silent mutations

These do not change the amino acid sequence and do not affect the function of a protein

39

Nonsense mutation

Has a stop codon in the middle of a sequence. The proteins lose their 3D shape and their functionality

40

Missense mutation

Substitution if one amino acid for another in the polypeptide. This has little effect on function of the protein

41

Vertical gene transfer

When genetic information in DNA is transmitted from parents to offspring during reproduction

42

Horizontal gene transfer

The DNA from one genome from one organism is transmitted to another. The cell that gives DNA is a donor cell.

43

Three main mechanisms of a horizontal transfer

Transformation
Conjugation
Transduction

44

Transformation

DNA from dead bacteria is taken up by live bacteria

45

Conjugation

DNA moves from one live bacteria to another

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Transduction

A virus moves DNA from one live bacteria to another

47

Endospores

Endospores can can survive extreme conditions

48

Operon

A cluster of gene related functions that are co-regulated

49

Promoter

A stretch of regulatory DNA where the RNA polymerase binds

50

Inducible operons

Genes that are usually turned off unless they are needed

51

Repressible operons

Genes are usually turned on unless there is a signal to turn them off

52

Cloning vector

A small piece of DNA, taken from a virus, plasmid, or an organism that can be maintained and into a foreign DNA fragment can be inserted for cloning purposes

53

Quorum sensing

Regulation of a gene expression in response to fluctuations in cell population density. Quorum sensing bacteria produce and release chemical signal molecules called auto-inducers that increase in concentration as a function of cell density

54

Periplasm

A concentrated gel like matrix in the space between the inner cytoplasmic membrane and bacterial outer membrane

55

What are exons?

Information carrying regions of eukaryotic genes