Lipids

1. 1[blank_start]lipids[blank_end] = a member of a broad group of compounds that include [blank_start]fats[blank_end], oils, waxes, steroids and various resins
   - many different chemical and [blank_start]physical[blank_end] structures > these are responsible for very defining characteristics

   1. Alipids
   2. Bfats
   3. Cphysical
2. 2Lipids are [blank_start]insoluble[blank_end] in water and polar substances
   
   but lipids are [blank_start]soluble[blank_end] in non-polar (organic) solvents such as chloroform
   

   1. Ainsoluble
   2. Bsoluble
3. 3Lipids have many different functions due to how chemically [blank_start]diverse[blank_end] they can be in their structure > lots of diversity in [blank_start]structure[blank_end] = lots of diversity in function

   1. Adiverse
   2. Bstructure
4. 4Lipids can be involved in [blank_start]storage[blank_end]
   - store of [blank_start]energy[blank_end] in fats and oils
   e.g. in [blank_start]adipose[blank_end] tissue in animals, oils in oil seeds e.g. sunflower

   1. Astorage
   2. Benergy
   3. Cadipose
5. 5Lipids can also have a structural function
   - protection = [blank_start]waxes[blank_end] on leaves, [blank_start]lanolin[blank_end] on wool gives it waterproofing and protections, [blank_start]adipose[blank_end] tissue around organs e.g. [blank_start]perirenal[blank_end] adipose tissue around the kidney protects from impact
   
   insulation = [blank_start]subcutaneous[blank_end] adipose tissue (under the cuticle) acts as an insulation barrier under skin, this is very important in [blank_start]hibernating[blank_end] animals
   
   [blank_start]membranes[blank_end] = provide non-[blank_start]polar[blank_end] barrier around cell and cell organelles separating aqueous environments (compartmentalisation) --> this is one of the [blank_start]most[blank_end] important structural roles of lipids
   
   [blank_start]metabolic[blank_end] control via [blank_start]steroid[blank_end] hormones and eicosanoids; fat soluble [blank_start]vitamins[blank_end] (A,D,E,K)
   
   industrial uses > manufacture of food oils; margarines and shortenings; oil-seed cakes for animal feeds, industrial oils and biodiesel; soaps; varnishes and [blank_start]paints[blank_end]; cosmetics and pharmeceuticals

   1. Awaxes
   2. Blanolin
   3. Cadipose
   4. Dperirenal
   5. Esubcutaneous
   6. Fhibernating
   7. Gpolar
   8. Hmost
   9. Imembranes
   10. Jmetabolic
   11. Ksteroid
   12. Lvitamins
   13. Mpaints
6. 63 types of lipids
   
   [blank_start]FATTY[blank_end] ACIDS = building blocks for making bigger and more [blank_start]complex[blank_end] lipids
   
   TRIACYLGLYCEROLS = [blank_start]energy[blank_end] stores (triglycerides)
   
   PHOSPHOACYLGLYCEROLS = membranes, also called [blank_start]phospholipids[blank_end]

   1. Acomplex
   2. BFATTY
   3. Cenergy
   4. Dphospholipids
7. 7NOTE: fatty acids are the building blocks for making bigger and more [blank_start]complex[blank_end] lipids, however this is not as simple as how [blank_start]amino[blank_end] acids make proteins
   - lipids can come together with other molecules to make a complex lipid --> not [blank_start]only[blank_end] fatty acids

   1. Acomplex
   2. Bamino
   3. Conly
8. 8[blank_start]Fatty[blank_end] acids
   - made of 2 components: hydrocarbon '[blank_start]tail[blank_end]'
   - [blank_start]carboxyl[blank_end] group 'head' (-COOH)
   
   

   1. AFatty
   2. Btail
   3. Ccarboxyl
9. 9The hydrocarbon [blank_start]tail[blank_end] of fatty acids is [blank_start]non[blank_end]-polar and [blank_start]only[blank_end] made of hydrogen and [blank_start]carbon[blank_end]

   1. Atail
   2. Bnon
   3. Ccarbon
   4. Donly
10. 10The [blank_start]carboxyl[blank_end] group 'head' of fatty acids has [blank_start]2[blank_end] polar groups
    - C=O
    - O-H
    
    The [blank_start]hydrocarbon[blank_end] tail is also called the [blank_start]acyl[blank_end] group of acyl chain

    1. Acarboxyl
    2. B2
    3. Cacyl
    4. Dhydrocarbon

11. 11because the carboxyl head of fatty acids has [blank_start]2[blank_end] polar groups (C=O, O-H), this means we are introducing polarity to into the molecule
    - the head is particularly polar
    - the polar nature of the head has a greater effect on [blank_start]shorter[blank_end] hydrocarbon chains
    - as the length of the hydrocarbon chain [blank_start]increases[blank_end] the polar effect of the head has a weaker effect

    1. A2
    2. Bshorter
    3. Cincreases
12. 12Fatty acids
    - [blank_start]short[blank_end] hydrocarbon tail = molecule has some polar properties
    - long hydrocarbon tail = molecule has very little [blank_start]polar[blank_end] character

    1. Ashort
    2. Bpolar
13. 13[blank_start]Short[blank_end] Chain Fatty Acids
    - also called [blank_start]volatile[blank_end] fatty acids (VFAs)
    - contain between 2-[blank_start]5[blank_end] carbon atoms in the molecule
    - [blank_start]volatile[blank_end] = have characteristic pungent odours
    - often produced by [blank_start]microorganisms[blank_end] during fermentation: in cheese, silage, vinegar, rumen and large bowl
    - they are [blank_start]miscible[blank_end] with water > will form a suspension with water > [blank_start]NOT[blank_end] soluble but because they have some [blank_start]polar[blank_end] characteristics due to polar nature of [blank_start]carboxyl[blank_end] group they will interact with [blank_start]water[blank_end] molecules to form a suspension rather than being in solution
    - VFAs are [blank_start]weak[blank_end] acids

    1. AShort
    2. Bvolatile
    3. C5
    4. Dvolatile
    5. Emicroorganisms
    6. Fmiscible
    7. GNOT
    8. Hpolar
    9. Icarboxyl
    10. Jwater
    11. Kweak
14. 14ethanoic acid is a [blank_start]short[blank_end] chain fatty acid (VFAs) with [blank_start]2[blank_end] carbon molecules, its trivial name is [blank_start]acetic[blank_end] acid

    1. Ashort
    2. B2
    3. Cacetic
15. 15propanoic acid, trivial name = [blank_start]propionic[blank_end] acid, has [blank_start]3[blank_end] carbon molecules therefore a short chain fatty acid (VFAs)

    1. A3
    2. Bpropionic
16. 16butanoic acid, also called [blank_start]butyric[blank_end] acid, has [blank_start]4[blank_end] carbon molecules and therefore is a short chain fatty acid/[blank_start]volatile[blank_end] fatty acid

    1. Abutyric
    2. B4
    3. Cvolatile
17. 17Long chain fatty acids
    - contain more than [blank_start]5[blank_end] carbon atoms
    - naturally occurring long chain fatty acids normally have an [blank_start]even[blank_end] number of carbon atoms
    - very important as part of more [blank_start]complex[blank_end] lipid molecules
    - they don't tend to be found in their [blank_start]free[blank_end] form in biological systems > they are usually part of more [blank_start]complex[blank_end] molecule rather than just a simple long chain
    
    There are 2 types of long chain fatty acids
    - [blank_start]saturated[blank_end] = contain no C=C double bonds
    - [blank_start]unsaturated[blank_end] = contain 1 or more C=C double bonds

    1. A5
    2. Beven
    3. Ccomplex
    4. Dfree
    5. Ecomplex
    6. Fsaturated
    7. Gunsaturated
18. 18[blank_start]Saturated[blank_end] Long Chain Fatty Acids
    - no double C=C bonds
    - have the [blank_start]general[blank_end] formula CH3(CH2)nCOOH
    - many molecules of the same type of fatty acid (saturated/non-saturated) can pack closely together and [blank_start]interact[blank_end]
    - the [blank_start]longer[blank_end] the hydrocarbon tail the [blank_start]more[blank_end] interactions > an [blank_start]increase[blank_end] in melting point with an increase in chain length
    
    as the chain length [blank_start]increases[blank_end] there are more interactions so more [blank_start]energy[blank_end] is required to break the interactions between chains therefore [blank_start]melting[blank_end] point increases
    
    if fatty acid chains are [blank_start]shorter[blank_end] they still pack together however there are less [blank_start]interactions[blank_end], so less [blank_start]energy[blank_end] is required to break the interactions therefore have a lower [blank_start]melting[blank_end] point

    1. ASaturated
    2. Bgeneral
    3. Cinteract
    4. Dlonger
    5. Emore
    6. Fincrease
    7. Gincreases
    8. Henergy
    9. Imelting
    10. Jshorter
    11. Kinteractions
    12. Lenergy
    13. Mmelting
19. 19[blank_start]Hexadecanoic[blank_end] (16C) acid = Palmitic acid has a melting point of 60.7
    
    [blank_start]Octadecanic[blank_end] (18C) acid = Stearic acid has a melting point of 69.6

    1. AHexadecanoic
    2. BOctadecanic
20. 20[blank_start]Unsaturated[blank_end] long chain fatty acids
    - unsaturated contain 1 or more carbon-carbon [blank_start]double[blank_end] bonds in the hydrocarbon ([blank_start]acyl[blank_end] chain)
    
    unsaturated fatty acids can have 2 configurations:
    - [blank_start]trans[blank_end] = the hydrogen atoms involved in the C=C are on opposite sides
    - [blank_start]cis[blank_end] = the hydrogen atoms involved in the C=C are on the same side
    
    [blank_start]Cis[blank_end] is the normal transformation; trans usually occurs alot in industry

    1. AUnsaturated
    2. Bdouble
    3. Cacyl
    4. Dtrans
    5. Ecis
    6. FCis
21. 21Cis configuration of [blank_start]unsaturated[blank_end] fatty acids
    - cis configuration puts a [blank_start]kink[blank_end] in the molecule this makes it difficult for the molecules to [blank_start]pack[blank_end] together as a linear molecule
    

    1. Akink
    2. Bunsaturated
    3. Cpack
22. 22The melting points of unsaturated fatty acids
    - when compared to a [blank_start]saturated[blank_end] fatty acid of the SAME chain length
    - the melting point/temperature is [blank_start]lower[blank_end] in the unsaturated fatty acid for the molecules [blank_start]cannot[blank_end] pack as closely together so there are less [blank_start]hydrophobic[blank_end] interactions between the [blank_start]acyl[blank_end] chains therefore [blank_start]less[blank_end] energy is required to break these interactions

    1. Asaturated
    2. Blower
    3. Ccannot
    4. Dhydrophobic
    5. Eacyl
    6. Fless
23. 23What happens to the melting temperature of unsaturated fatty acids with each additional double bond added?
    - every time we add a [blank_start]double[blank_end] bond the melting point [blank_start]decreases[blank_end] even further
    - every time we impair the ability of the chains to [blank_start]pack[blank_end] together
    - we are making it easier to break the interactions so [blank_start]less[blank_end] energy is required

    1. Adouble
    2. Bdecreases
    3. Cpack
    4. Dless
24. 24The melting point of long chain fatty acids is determined by the [blank_start]length[blank_end] of the chain, the longer the chain the more [blank_start]interactions[blank_end] and therefore more [blank_start]energy[blank_end] is required to break these, resulting in a [blank_start]higher[blank_end] melting point

    1. Alength
    2. Binteractions
    3. Cenergy
    4. Dhigher
25. 25There are 2 ways to number carbon atoms
    - the most conventional way = the first carbon atom is the one involved in the [blank_start]carboxyl[blank_end] group, the 2nd carbon is referred to as the [blank_start]alpha[blank_end] carbon, the 3rd [blank_start]beta[blank_end] and the last carbon in the chain is called [blank_start]zeta[blank_end] carbon
    
    - the less conventional way is the opposite, from the [blank_start]methyl[blank_end] group (CH3), this is called the [blank_start]omega[blank_end] system

    1. Acarboxyl
    2. Balpha
    3. Cbeta
    4. Dzeta
    5. Emethyl
    6. Fomega
26. 2618 C fatty acids
    - 18C saturated fatty acid = octadecanic acid also called [blank_start]stearic[blank_end] acid
    - 18:1 is called octadecanoic acid or [blank_start]oleic[blank_end] acid
    - 18:2 is called [blank_start]octadecadienoic[blank_end] or linoleic acid

    1. Aoleic
    2. Boctadecadienoic
    3. Cstearic
27. 27Fatty Acid Reactions
    - fatty acids react with alcohol to form [blank_start]esters[blank_end] and water in a [blank_start]condensation[blank_end] reaction
    
    Fatty acids can released from esters by a [blank_start]hydrolysis[blank_end] reaction (uses water) to make fatty acids and [blank_start]alcohol[blank_end]
    - this does [blank_start]not[blank_end] happen easily but H2O can be replaced by [blank_start]NaOH[blank_end] then have a similar reaction called saponification

    1. Aesters
    2. Bcondensation
    3. Chydrolysis
    4. Dalcohol
    5. ENaOH
    6. Fnot

Description

Biochemistry Quiz on Lipids, created by sophie waddington on 26/04/2018.

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sophie waddington

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