Exam (elaborations)
Biochemistry Review Chapters 10, 13, 14, & 15
- Course
- Institution
Biochemistry Review Chapters 10, 13, 14, & 15 Biochemistry Review Chapters 10, 13, 14, & 15 Biochemistry Review Chapters 10, 13, 14, & 15
[Show more]
Content preview
Biochemistry Review Chapters: 10, 13, 14, & 15Chapter 10: Lipids
• Biological Functions of Lipids:
o Storage of energy
▪ Reduced compounds: lots of available energy
▪ Hydrophobic nature: good packing
o Insulation from environment
▪ Low thermal conductivity
▪ High heat capacity (can “absorb” heat)
▪ Mechanical protection (can absorb shocks)
o Water repellant
▪ Hydrophobic nature: keeps surface of the organism dry
• Prevents excessive wetting (birds)
• Prevents loss of water via evaporation
o Buoyancy control and acoustics in marine mammals
▪ Increased density while diving deep helps sinking (just a hypothesis)
▪ Spermaceti organ may focus sound energy: sound stun gun?
• More functions:
o Membrane structure
▪ Main structure of cell membranes
o Cofactors for enzymes
▪ Vitamin K: blood clot formation
▪ Coenzyme Q: ATP synthesis in mitochondria
o Signaling molecules
▪ Paracrine hormones (act locally)
▪ Steroid hormones (act body-wide)
▪ Growth factors
▪ Vitamins A and D (hormone precursors)
o Pigments
▪ Color of tomatoes, carrots, pumpkins, some birds
• Depending on wave lengths is what gives off color
o Antioxidants
▪ Vitamin E
• Classification of lipids:
o Based on the structure and function
▪ Lipids that do not contain fatty acids: cholesterol, terpenes,…
▪ Lipids that contain fatty acids (complex lipids)
• Can be further separated into
o Storage lipids and membrane lipids
,• Fatty Acids:
o Complete oxidation to CO2 and H2O
o Carboxylic acids with hydrocarbon chains containing between 4 to 36 carbons
▪ Even #-- every acetyl group
▪ Almost all natural fatty acids have an even number of carbons
▪ Most natural fatty acids are unbranched
▪ Saturated: no double bonds between carbons in the chain
▪ Monounsaturated: one double bond between carbons in the alkyl chain
▪ Polyunsaturated: more than one double bond in the alkyl chain
▪ May contain ring structures
o Chain length: number of double bonds
• How many carbons
• Where the double bonds reside
▪ Double bond position given by a Δ followed by the number of the
carbon, which is participating in the double bond. Note that the
carboxyl group carbon is C-1
o Solubility and Melting point of fatty acids:
▪ Solubility (largely determined by chain length and degree of saturation of the
hydrocarbon chain)
▪ Decreases as the chain length increases
▪ Longer fatty acid chain
• Decrease solubility
• Increase melting point
▪ Shorter fatty acid chain
• Increase solubility
• Decrease melting point
▪ Fewer double bonds, less soluble
▪ Melting Point (Influenced by length and degree of unsaturation of the
hydrocarbon chain)
• Decreases as the chain length decreases
• Decreases as the number of double bonds increases
• At room temp the saturated fatty acids from 12:0 to 24:0 are
waxy while the corresponding unsaturated fatty acids are oily
liquids
• Differences due to the degree of packing of the molecules
• For saturated fatty acids melting point increases
• Longer chain- increase
• Double bond present- dramatically decrease melting point
o Saturated fatty acids pack in a fairly orderly way
▪ Extensive favorable interactions
o Unsaturated cis fatty acid pack less orderly due to the kink
▪ Less-extensive favorable interactions
o It takes less thermal energy to disrupt disordered packing of unsaturated fatty acids:
▪ Unsaturated cis fatty acids have a lower melting point
o Trans fatty acids can pack more regularly and show higher melting points than cis forms
• Triacylglycerols:
o In vertebrates, free fatty acids with a free carboxylate
group are bound to a protein carrier called serum albumin
o Majority of fatty acids in biological
systems are found in the form of
triacylglycerols
o Solid ones are called fats, liquid ones are called oils
, o The primary storage form of lipids (body fat)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller examiner123. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $17.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
82215 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now