Exam 1: Cell Structure & Regulation of Phenotype

Question 1

What is the definition of a cell? How can it be described as?

Answer 1

The basic unit of a cell
1. It has specialized functions
2. Continual turnover in some tissues
3. Generally 10-30 μm in diameter

Question 2

What does a plasma membrane do? What is it surrounded by?

Answer 2

1. Regulates what enters and exits the cell
2. Surrounded by a lipid bi-layer

Question 3

What is a Cytoskeleton?

Answer 3

A network of protein filaments and tubules in cell

Question 4

What are some examples of Nucleotides?

Answer 4

1. Nucleic acids (DNA, RNA)
2. ATP

Question 5

What are some examples of protein?

Answer 5

1. Enzymes
2. structural (e.g., cytoskeleton)

Question 6

What are examples of carbohydrates?

Answer 6

1.Glucose
2.Glycogen

Question 7

What are examples of Lipids?

Answer 7

1. Triglycerides
2. Phospholipids
3. Cholesterol

Question 8

What are some examples of Inorganic (ash)?

Answer 8

1. Ca
2. Mg
3. Fe
4. Zn
5. Na

Question 9

What is a cell phenotype?

Answer 9

Central dogma of biology, it is a conversion of genetic information to a functional product

Question 10

How does the process of go?

Answer 10

Goes from DNA (it can do replication) -> RNA via transcription-> Protein via Translation -> Phenotype

Question 11

What does DNA contain in its strands what is it called?

Answer 11

Called deoxyribonucleotides

Question 12

What does RNA contain in its strand?

Answer 12

Ribonucleotides

Question 13

What is conversion of genetic information to functional product look?

Answer 13

DNA->mRNA-> Polypeptide (protein)

Question 14

How is DNA determined?

Answer 14

1. Gene sequence
2. Epigenetic modification

Question 15

How is RNA determined?

Answer 15

Determined by regulation of gene transcription

Question 16

How is protein determined?

Answer 16

Determined by regulation of protein and post-translational modifications.

Question 17

How can DNA be described as?

Answer 17

All the instructions- neatly packed away

Question 18

What efficiently packages DNA to fit the nucelus? What can DNA control?

Answer 18

1. Chromatin
2. Control DNA replication and gene expression

Question 19

How does the formation of a double helix occur?

Answer 19

Starts from a Chromosome-> Chromatin-> forming a Heterochromatin-> forms Euchromatin with histones -> turns into Nucleosomes -> Double helix that is 5-6 ft long.

Question 20

What is single-nucleotide polymorphisms (SNPs)?

Answer 20

It is when there is a one-nucleotide difference within a gene, that is either silent or expressed, between members of a biological species

Question 21

What are copy number varations (CNVs)?

Answer 21

They are addition or loss of longer segments of genomic DNA by chromosomal rearrangements

Question 22

What are SNPs and CNV associated with?

Answer 22

Associated with development and disease

Question 23

What are Quantitative trait loci (QTLs)?

Answer 23

Genetic variant that are linked to a specific, quantitative trait (for example: milk production)

Question 24

What are some some example of how SNPs affect animal health?

Answer 24

1. Polysaccharide storage myopathy (PSSM) (G>A)
2. Porice stress syndrome/Malignant hyperthermia (C>T)
3. Predictor of optimum racing distance (C>T)
4. Spider lamb syndrome T>A

Question 25

What does an AA subsitution in Gylcogen synthase, ryanodine receptor do?

Answer 25

1. Causes over activation of enzyme Glycogensis, Myopathy 2. Over activation of the receptor can cause too much muscle contraction, hyperthermia

Question 26

Would a DNA sequence be the same between different cells? Like a muscle and kidney cell? | Same body

Answer 26

They would have an identical sequence but different functions

Question 27

What are some examples of Epigenetic modifications?

Answer 27

1. Affect phenotype by regulating access to the DNA for transcription (gene expression) 2. Does not change the DNA sequence 3. Modifications to the DNA or histones

Question 28

When it comes to regulation of a cell phenotype what does the control transcriptional do?

Answer 28

Regulates which genes are transcribed or rate at which transcription occurs | chromatin -> DNA unpacking-> Gene available for transcription -> Transcr

Question 29

When it comes to regulation of a cell phenotype what does the control Post-transcriptional do?

Answer 29

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

Question 30

When it comes to regulation of a cell phenotype what does the control Translational do?

Answer 30

1. How often and how rapidly mRNA transcripts are translated into proteins 2. Length of time it takes for mRNA to be activated & speed at which mRNA is degraded | mRNA in cytoplasm -> translation/ degredation-> Polypeptide

Question 31

When it comes to regulation of a cell phenotype what does the control Post-translational do?

Answer 31

1. Many proteins require processing before they become functional 2. Several control mechanisms affect rate at which proteins becomes active and time it remains functional ## Footnote Cleavage Modification transport to destination -> Functional protein (subject to modifications)-> Degradation

Question 32

What does the Non-coding RNA consist of? What is its role?

Answer 32

1.~ nucleotides long 2.Important repressors of gene expression * Blocks translation * Destabilize mRNA * Cleave mRNA

Question 33

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?

Answer 33

1. If a paternal is +, and maternal is + = Unaffected phenotype 2. Paternal +, Maternal CLPG= Unaffected 3. Paternal CLPG, Maternal + = Muscle hypertrophy 4. Paternal CLPG, Maternal CLPG = Unaffected

Question 34

What does amino acid sequence affect ?

Answer 34

1. The shape & three dimensional structure of protein 2. Function 3. How the protein may assemble with other proteins

Question 35

How does regulating a protein function work?

Answer 35

1. Transport to sub-cellular location 2. Structure folding ( confirmation) 3. Post translational modifications (Phosphorylation, Methylation, Acetylation, Oxidation/reduction, other) 4. Cleavage ( removal of pro-peptides) 5. Addition/binding of co-factors

Question 36

What does Protein degradation consist of?

Answer 36

1. Remove damaged proteins 2. Control protein activity (hormones have short life-span) 3. Liberate AA for synthesis of other proteins, or for energy sources.