Eukaryotic Genome_Exam 3 Flashcards
Every cell with a nucleus contains the same _____
genome
Only specific genes are ____ in each cell
expressed
_____ genes are encoded by DNA in the Nucleus
21,000
Nucleus contains information from ____ & ____
mother/father
In the Human genome; the mitochondria has how many genes?
37
Nitrogenous base =
Purine or pyrimidine
Guanine and Adenine for both DNA and RNA
Purines
Thymine and cytosine for DNA; Uracil and Cytosine for RNA
pyrimidines
Nucleoside =
Base +Sugar
Base + Sugar + Phosphate =
Nucleotide
DNA building blocks are made of what 4 bases?
2 purines: A,G
2 pyrimidines: C, T
DNA building blocks are held together by ?
complementary pairing
DNA building blocks are the backbone of _____
Deoxyribose (5 carbon sugar)
Eukaryotic DNA with unique DNA sequence (genes) they encode for?
proteins
Eukaryotic DNA > repeat sequences > Dispersed repetitive > ___ & ____
LINES / SINES
Eukaryotic DNA > repeat sequences > Satellite DNA > ___ ____ ____
Alpha (171 bp)
Mini (20 - 70 bp)
micro (2-4 bp)
Genes are the complete sequence region necessary for what?
generating a product
Genes are located in ____ & in _____
chromosomes & in mitochondria
Genes contain ___ and ____ regions
promoters & control regions
Euchromatin =
loosely packed
Densely packed regions where chromosomes are stored that are genetically inactive?
Heterochromatin
Euchromatin is _____ active, and gene sequence available to ____ ____
Transcriptionally; RNA polymerases
DNA repeats at chromosome ends that protect it from degradation, this structure is called what?
Telomere
This structure, attached during mitotic (M phase) of cell cycle
Centromere
Number of chromosome copies in a cell =
ploidy
Most cells in the body are ___-
diploid
Germ cells (____ & ____) are ____ (1 copy)
sperm & oocytes; are haploid
Haploid genome has ____ bp
3 billion
haploid genome has ___ chromosomes (__ somatic, __ sex)
23, 22, 1
Haploid genome has enough DNA to code for ____ genes
1.5 million genes
Haploid genome really only codes for about ____ - ____ genes
20,000 - 25,000
____ - collection of all proteins expressed by organism, much larger number than protein encoding genes
proteome
___ - influence mRNA expression
microRNAs
_____ - Alternative splicing of mRNA
posttranscriptional modifications
____ - acetylation of histone proteins
histone acetylation
____ - methylation of cytosine residues in DNA
DNA methylation
These are Arginine & lysine - rich basic proteins. They have positive charge on AA that helps bind to negative charge on DNA sugar phosphate
Histones
Acetylation of lysine weakens _____ which make it easier for ____ factors to access
DNA-histone interaction; transcription
Acetylation/Deactylation of lysine occurs by what?
Histone acetyl transferases (HATs)
This makes interactions tighter & is associated with gene silencing
Histone deacetylase (HDAC)
Hypomethylation - genes are ____
on
hypermethylation - genes are ____
off
Acetylation histones gene expression is ____
on
Deacetylation histones gene expression is ___
off
Epigenetics: stable changes to a gene structure, without changing what?
DNA sequence
Epigenetics ____ gene expression
alter
Alterations in gene expression due to epigenetics can be what?
passed down through generations (genetic imprinting)
Epigenetics are controlled by what?
- methylation of cytosines
- tissue - specific chromatin alterations (acetylation)
____ are influenced by what you eat
epigenetics
____ ____ during pregnancy impacts gene expression
food consumption