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Building Blocks of Life

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krabi's version from 2015-07-23 21:24

Section

Question Answer
What is a Fatty Acid?Long chain of carbon with a carboxylic acid at the end & Even number of carbons
Saturated Fatty AcidSingle C-C bonds
Unsaturated FA?One or more C=C db’s
How to get energy from fats?Oxidation releases large amount of energy in Fatty Acids
What is a Triglyceride?Also termed as Triglyceralides w/ 3 Carbon backbone called glycerol
How are triglycerides stored?When it makes up most of cell ⇒ results in an adipocyte
What is cholesterol?Cholesterol is an important component of plasma membranes, increasing fluidity of the membrane; is also the precursor to steroid hormones and bile.
What is a Phospholipid?Glycerol backbone w/ polar phosphate group that replace 1 FA & Amphipathic & Has 2 FA’s
What is dietary fat broken down into before absorption?2 fatty acids + 1 monoglyceride; Dietary fat is broken into two fatty acids and one monoglyceride prior to absorption.
Lipase triglycerides are broken down into two fatty acids and a monoglyceride before absorption and ultimate reassembly into a triglyceride in the enterocyte.
Give an EXCEPTIONNote that triglycerides are dietary fat, which are also known as triacylglycerol, and neither are therefore breakdown products.
What is a Glycolipid?Like a phospholipid but has a carb attached to the 3C glycerol backbone & Amphipathic
Where are Glycolipids?Found in myelinated neural cells
What is a steroid?Ringed Vitamin , cholesterol and hormones
TerpenesInclude form of VItamin A
What is an Eicosanoid?20C lipid eg. Prostaglandin; Part of hormones that regulate blood pressure, smooth muscle contraction and body temp
How do lipids travel?All lipids transported via lippoproteins ⇒ able to dissolve lipids in hydrophobic core, but moves freely w/hydrophillic shell
How does density play a role?Classified by density; More LIPIDPROtein (lower the density)
2ndary protein structure?Both parallel and anti-parallel directionality of strands in the sheet
How do amino acids bond 2nd level?H.bonds ⇒ carbonyl oxygen + H in amino group
What 4 forces influence 3rd & 4th structure?1.Covalent disulfide bonds (w/2 cysteine aa on chain) 2.Ionic interactions between acidic & basic side chains 3.H.bonds 4.Hydrophobic side chains
What can aa Proline do?Is anarchist. Disruptors secondary 2nd formation
What are Cytochromes?Proteins that needs a crutch ie. prosthetic heme group eg. in ETC and hemeglobin
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Section

What is glucose? 6C; Exists in aqueous solution with equilbrium that favours ring form over chain form
Question Answer
Liver and sugar?It converts most carbs to glucose anyway
Difference between alpha & beta glucose better for the OH to Be Up in the 1C eg. cellulose
What is Glycogen?Starch and glycogen are alpha versions
What eats glucose?Animals eat alpha links and bacteria break beta linkages
OIL RIG for glycogen?Easy to oxidize glucose to ATP & When cell has enuf ATP, glucose turn into glycogen or fat or polymerized into polysaccaride
What is Starch?Plain glucose
AmyloseCellulose isomer; Branched & unbranched, alpha linkages
Amylpecticlooks like glycogen but has branching
How is DNA bonded?The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate phosphodiester backbone.
What is the backbone of DNA?The acidic TriPhosphate groups with the Ribose sugar
What is the basic building block of DNA?The DNTP ie. deoxyribonucleoside triphosphate
What is a nucleoside?It is the ribose with an aromatic base.
Where is the base and triphosphates linked to the ribose?Like a necklace with a clasp. The 1 C is linked to a purine/pyramadine. The phosphate ester is linked to the 5C.
What are the differences between RNA and DNA?Has a ribose instead of a deoxyribose - The missing reactive OH; Is single stranded; Has uracil instead thyamine (there is no thyme!).
Why is uracil important?Uracil - Less energy costly to make and manage; The 2 OH group nucleophillically attacks the phosphate backbone resulting in a leaving group.
How is the binding significant of the aromatic base to the ribose+phosphate backbone?In the specific binding of the bases.
How are Nucleotides specifically bound?They are covalently linked by phosphodiester bonds; The 3 OH group + the 5 group of the next Phosphate group.
What is hydrogen bound in DNA?The strong H.bonds between the purines and the pyradamines.
Why is the pyrophosphate important?When it is hydrolyzed, it is thermodynamically favourable to linked up DNA likes beads on a string.
What are important DNA structural components?It is double stranded (unlike RNA); It is right handed like people; It is complementary and anti-parallel; You can bind it together with annealing or hybridization
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Section

Question Answer
What stabilizes the DNA?Van der waals between the aromatic bases; There are hydrophobic reactions amongst the bases. (NOT H.bonds)
What is the width of base?20 A
How often does it turn?Every 10 base pairs or 34 A.
SPONTANEOUS DEAMINATIONLoss of Nitrogen group that can result in a genetic mutation.
HELICASEEnzyme that unwinds at the start of DNA replication
ORIGIN OF REPLICATIONWhere the helicase starts DNA replication. A specific sequence of nucleotides that are recognized by enzymes such as helicase, topoisomerase, etc.
TOPOISOMERASERelieves tension on the DNA strand once it has been unwound.
OPEN COMPLEXNickname for the separated strands.
LAGGING STRANDThe top strand that is anti-parallel to her sister. She gets Okazaki fragments as a stop gap measure. Has a stop and start replication because she has to wait for her sister to finish and for the replication fork to widen.
OKAZAKI FRAGMENTSSmall DNA chunks
LEADING STRANDBottom leader that is polymerising from 5’-3’
LIGASEEnzyme that comes in at the end and stiches everything together
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Section

Question Answer
What is the difference between a point mutation and insertion/deletion mutations?Point mutations are about a single base pair mistake; a purine for a pyradimine gets dropped in; in contrast insertion/deletion are about an entire codon (3 amino acids) or nucleotide appearing or disappearing. Also - it leads to frameshift which results in diseases. Note, not all insertions or deletions can lead to frameshift.
Why is Frameshift dangerous?because it can lead to stopping translation e.g. incomplete protein production.
3 kinds of Point MutationsMissense, Nonsense, Silent
MissenseWhere the wrong amino acid is replaced. If there is little impact, it can be called a conservative mutation.
NonsenseA Stop codon accidentally gets in. ‘Stop this Nonsense!’
SilentThere are some redundant codons, but they have no impact
What are Translation errors?They are not genetic errors. A mutation is a permanent change in genetic code and a thymine dimer which is successfully repaired would not therefore be categorized as a mutation.
2 Conditions for Mutation?1.Any time a frameshift (a change in reading frame for a protein) OR, 2.transversion (substitution of a purine for pyrimidine or vice versa) takes place, a mutation has occurred. In the instances where a change in genetic code occurred but no change in the translated protein occurred, a silent mutation has taken place (which is still a mutation).
What is the Mutation Exception?Exposure of DNA to UV light generating a thymine dimer which is replaced with individual thymines via nucleotide excision repair
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