Exam 1: Cell Structure & Regulation of Phenotype Flashcards
What is the definition of a cell? How can it be described as?
The basic unit of a cell
1. It has specialized functions
2. Continual turnover in some tissues
3. Generally 10-30 μm in diameter
What does a plasma membrane do? What is it surrounded by?
- Regulates what enters and exits the cell
- Surrounded by a lipid bi-layer
What is a Cytoskeleton?
A network of protein filaments and tubules in cell
What are some examples of Nucleotides?
- Nucleic acids (DNA, RNA)
- ATP
What are some examples of protein?
- Enzymes
- structural (e.g., cytoskeleton)
What are examples of carbohydrates?
1.Glucose
2.Glycogen
What are examples of Lipids?
- Triglycerides
- Phospholipids
- Cholesterol
What are some examples of Inorganic (ash)?
- Ca
- Mg
- Fe
- Zn
- Na
What is a cell phenotype?
Central dogma of biology, it is a conversion of genetic information to a functional product
How does the process of go?
Goes from DNA (it can do replication) -> RNA via transcription-> Protein via Translation -> Phenotype
What does DNA contain in its strands what is it called?
Called deoxyribonucleotides
What does RNA contain in its strand?
Ribonucleotides
What is conversion of genetic information to functional product look?
DNA->mRNA-> Polypeptide (protein)
How is DNA determined?
- Gene sequence
- Epigenetic modification
How is RNA determined?
Determined by regulation of gene transcription
How is protein determined?
Determined by regulation of protein and post-translational modifications.
How can DNA be described as?
All the instructions- neatly packed away
What efficiently packages DNA to fit the nucelus? What can DNA control?
- Chromatin
- Control DNA replication and gene expression
How does the formation of a double helix occur?
Starts from a Chromosome-> Chromatin-> forming a Heterochromatin-> forms Euchromatin with histones -> turns into Nucleosomes -> Double helix that is 5-6 ft long.
What is single-nucleotide polymorphisms (SNPs)?
It is when there is a one-nucleotide difference within a gene, that is either silent or expressed, between members of a biological species
What are copy number varations (CNVs)?
They are addition or loss of longer segments of genomic DNA by chromosomal rearrangements
What are SNPs and CNV associated with?
Associated with development and disease
What are Quantitative trait loci (QTLs)?
Genetic variant that are linked to a specific, quantitative trait (for example: milk production)
What are some some example of how SNPs affect animal health?
- Polysaccharide storage myopathy (PSSM) (G>A)
- Porice stress syndrome/Malignant hyperthermia (C>T)
- Predictor of optimum racing distance (C>T)
- Spider lamb syndrome T>A
What does an AA subsitution in Gylcogen synthase, ryanodine receptor do?
- Causes over activation of enzyme Glycogensis, Myopathy
- Over activation of the receptor can cause too much muscle contraction, hyperthermia
Would a DNA sequence be the same between different cells? Like a muscle and kidney cell?
Same body
They would have an identical sequence but different functions
What are some examples of Epigenetic modifications?
- Affect phenotype by regulating access to the DNA for transcription (gene expression)
- Does not change the DNA sequence
- Modifications to the DNA or histones
When it comes to regulation of a cell phenotype what does the control transcriptional do?
Regulates which genes are transcribed or rate at which transcription occurs
chromatin -> DNA unpacking-> Gene available for transcription -> Transcr
When it comes to regulation of a cell phenotype what does the control Post-transcriptional do?
1.mRNA molecules undergo changes in nucleus before translation occurs
2.Introns are removed & exons spliced together
Pre-mRNA-> RNA processing-> mRNA-> Transport to cytoplasm
When it comes to regulation of a cell phenotype what does the control Translational do?
- How often and how rapidly mRNA transcripts are translated into proteins
- Length of time it takes for mRNA to be activated & speed at which mRNA is degraded
mRNA in cytoplasm -> translation/ degredation-> Polypeptide
When it comes to regulation of a cell phenotype what does the control Post-translational do?
- Many proteins require processing before they become functional
- Several control mechanisms affect rate at which proteins becomes active and time it remains functional
Cleavage Modification transport to destination -> Functional protein (subject to modifications)-> Degradation
What does the Non-coding RNA consist of? What is its role?
1.~ nucleotides long
2.Important repressors of gene expression
* Blocks translation
* Destabilize mRNA
* Cleave mRNA
Hard to explain but when it comes to polar overdominance inheritance how does it work? Coming from a paternal & a maternal side of things? How is the Phenotype affected?
- If a paternal is +, and maternal is + = Unaffected phenotype
- Paternal +, Maternal CLPG= Unaffected
- Paternal CLPG, Maternal + = Muscle hypertrophy
- Paternal CLPG, Maternal CLPG = Unaffected
What does amino acid sequence affect ?
- The shape & three dimensional structure of protein
- Function
- How the protein may assemble with other proteins
How does regulating a protein function work?
- Transport to sub-cellular location
- Structure folding ( confirmation)
- Post translational modifications (Phosphorylation, Methylation, Acetylation, Oxidation/reduction, other)
- Cleavage ( removal of pro-peptides)
- Addition/binding of co-factors
What does Protein degradation consist of?
- Remove damaged proteins
- Control protein activity (hormones have short life-span)
- Liberate AA for synthesis of other proteins, or for energy sources.
