Molecules - Carbohydrates - Lipids - BIOL107-T2

**MOLECULES - CARBOHYDRATES -LIPIDS P43** 02.1: **MOLECULES**  Carb: CHO Lipids - CHOP Proteins - CHONS Nucleic acids - CHONP  \- taken by an electric microscope \- Mostly water? ㄴ water is the MEDIUM \^\^  \- carbohydrates...

**MOLECULES - CARBOHYDRATES -LIPIDS P43** 02.1: **MOLECULES**  Carb: CHO Lipids - CHOP Proteins - CHONS Nucleic acids - CHONP  \- taken by an electric microscope \- Mostly water? ㄴ water is the MEDIUM \^\^  \- carbohydrates and proteins tend to vary a lot depending on the cell; lipids are more stable \-  \- Carbon Dioxide is inorganic: ㄴ WHY? \- Carbon Dioxide is inorganic: ㄴ WHY? ㄴ organic compounds include **covalent bonds** H-C or C-C, CO2 does not have these bonds  \- skeletal diagrams are what is usually used \- hexane: at the ends of the line and at the vertices, there are carbon atoms which are not shown (you show them by connecting them with lines) \- hexane has 6 atoms \- \-   \- ionic- di-pole \- list is ordered by strength -  Monomers combined = polymer DNA - polymer etc. Synthesis of complex organic molecules  dehydration reaction occurs during synthesis \- dehydration occur when combining monomers \- hydroxyl and hydrogen will be exposed, which form water (dehydration) since you\'re removing water \- you leave the valance shells empty by 1 electron on the molecules... this creates a covalent bond between the two molecules Monomer Dimer -trimer and onward  polymers Polymer branching is possible if there are suitable branching points \- polymers can be branched \- can interact with one or more of the monomers \- we use this technique for carb storage for energy  Hydrolysis is the opposite of dehydration synthesis \- ADD water (to retrieve monomer) \- break down by hydrolysis Hydrolysis occurs during breakdown of polymers CARBOHYDRATES 02.2  Monosaccharides Disaccharides Oligosaccharides polysaccharides \- get examples  monosaccharides \- ex: ribose, glucose, fructose, etc. \- 'ose' name given to sugars \- by definition, these are polyhydroxy aldehydes or \_\_\_ ketones ㄴ depends where the Oxygen is bonded (if it's on the second Carbon, it is a ketone) -carbonyl group Sugar alcohols \- missing the carbonyl group \- it has a hydroxyl group instead.  Glucose is central to many metabolic pathways Major source of carbon and energy E coli monosaccharides \- not linear - they're in rings \- because C1 or C2, will react with -xyl to form a ring \- 1 and 6-carbon monosaccharides are usually ring structures  Ring structures can take on different forms based on ring membership \- ring can be 5 or 6 sided; ㄴ ketones are usually 5ring- ㄴ 6 - Carbon 1 has the Oxygen to react with Carbon 5 \- polymers of each form have different properties \- if hydroxyl is pointing down - called alpha glucose; pointing up, beta glucose - same molecule with different shapes  Glucose mods and derivatives \- NAG glucosamine Disaccharides \- glucose is usually used for energy transport etc. for humans \- Dehydration reaction makes the ethyl bond when: glucose + fructose = sucrose  Oligosaccharides Short chain of simple sugars Fructans Found in plants Dietary component \- **short chain** \- \- polysaccharides \- long chains  glycogen \- main storage of carbohydrates in animals. (short term storage) ㄴ in liver, striated muscles. \- has a **protein core** \- carbon 1 is linking to carbon 4 in the other molecule (alpha 1-\>6) (a 1-\>4) \- plants store glucose in the form of starch \- longer term storage ㄴ **2 kinds of starches:** **Amylose:** no branching; only alpha 1-\>4 **Amylopectin:** has branching; rate of branching is much lower; has alpha 1-\>6 at the branching points  Cellulose Plant cells Most abundant natural polymer on earth Cotton is 90% cellulose Beta \- same linkage but different isomer... you end up with cellulose -**structural** component in plant cells; indigestible in terms of it being a source of energy \- making long chains that turn into microfibril (used as building material for a wall in the cell of a plant) Chitin \- **structural** \- exoskeleton; fungi cell walls \- NAG 1-\>4 \- chitin  Is this a monosaccharide? \- 1 aldehyde group = it's a monosaccharide \- monosaccharide: a carbon chain anywhere from 3-7 carbons which is a poly hydroxy aledhyde (many hydroxyl groups, and one aldehyde group (same as carbonyl group, whether it's on carbon 1 or 2))  **LIPIDS** 02.3  Organic molecules soluble in non-polar solvents \- not soluble in water as they don't have any hydroxyl groups \- broad class of molecules **- DO NOT for polymers** Fatty acids Palmitic acid 16:0 \- one specific class of molecule under lipids \- **hydrocarbon** that at one end, has a **carboxyl group** \- "alpha" is the carbon that forms the carboxylic group \- last carbon, (4-24) is **omega** (w) \- less solubility as you lengthen the chain; more as you shorten it \- 16.0 (16, number of Carbons; 0, zero double bonds) \- **saturated fatty acid (**saturated with hydrogen)  \- 16.1 (there is one double bond) \- bent because of the effect of the double bond (n-7) omega 7 fatty acid \- **unsaturated fatty acid** \- when you get a double bond (less hydrogens in general compared to fatty acid \^\^) Glycerol or glycerin \- not carb because it doesn't have the aldehyde group, only hydroxyl group \- useful for fatty acids to attach to \-  \- fatty acids attach to glycerol by esterification, through the dehydration reacion High density for storage \- when all 3 Carbons are attached to a fatty acid molecule, it is called a **fat** or an **oil** \- tri**acyl**glycerides \- used as medium to store other things in the fat which are fat soluble \- serve as energy storage in most organisms  \- **fats** are saturated and is **solid at room temperature** \- higher melting point \- butter is made from the fats found in milk Oil Oils are triglycerides where ethere is at least one unsaturation in at least one fatty acid. \- liquid at room temperature \- at least one double bond in at least one of the fatty acids \- common for plants to store oils; (we store fats, but plants also store fats)  Cis and trans fats \- both have a single double bond \- elaidic: solid at room temperature \- oleic: liquid at room temp \- one acts as if it is saturated \- because in the cis, they're pointing to one side, and in trans, they're pointing to different sides (shapes the molecule) \- elaidic acid - trans - striaght - solid \- poleic acid - cis - bent - liquid What causes the bend?? Double bonds are rotationally stable. Cis "the same" H atoms bound to either Cs on the same side. \- causes the **bend!** (position of Hydrogen) Trans "different" Bout to either Cs on **different sides**  Cis-trans isomerization Light energy causes lipid to isomerize \- shape change \- signal is interpreted by the brain Retinal is bound to proteins in the retina \- capturing light in the vision cycle \- made from vitamin A 11-cis retinal **phospholipids** Swap a fatty acid for a **phosphate** **- amphiphatic** \- phosphate **head** strongly **hydrophilic** \- one of the glycerol carbons has a phosphate group  **Amazing phospholipid** Ester bond, choline, containing N, attached to one of the Os in phosphate Amphiphatic )=amphiphilic) (has both hydrophilic and hydrophobic parts) \- main charge driving the phosphate head is nitrogen, but the phosphate itself is charged (polar) Phospholipid tails \- head (phosphate head) \- tails (fatty acids) \- tails can be saturated or unsaturated  Phospholipid packing density \- you can pack **fewer** molecules in the same space if one of the tails is **unsaturated** (so bent is unsaturated) \- causes the difference in melting point (if molecules are further apart, the melting point is lower, behaves more like a liquid and vice versa) Phospholipids spontaneously form a bi-layers \- in water and they are the basis of the cell membrane NOT the cell membrane Hydrophilic (polar) head Hydrophobic tali ㄴ naturally aggregate into this bi-layer  **Steroids** \- different class of lipids \- ex: cholesterol Steroids are used as signalling molecules in animals \- estradiol: kind of estrogen, one of the main ones Testosterone Vitmain D is based off cholesterol (that our body makes, we just modify it to serve other purposes)  \- ecdyson Insect molting hormone \- **Waxes** are another class of lipid: lipid chains of alkanes -carnauba wax \- waxes are hydrophobic \- used by organisms to limit their exposure to dehydration  **Glycolipids** \- also present in the cell membrane \- crucial to the immune response \- sugars - glycerol - fatty acids (difference is the sugar instead of the phosphate THUS the glyco instead of "phospho" Sugar molecule can be one or more sugar molecules \- reason why blood types exist Complex lipid-saccharide molecules **Lipopolysaccharides** \- structural component of the cell walls of some bacteria EColi ㄴ uses it as a means of protection Lipid A is responsible for the toxicity of the pathogenic bacteria ㄴ two main sugars ㄴ sugars are polar (faces out of the cell)  Energy reserves. Long term energy storage **Fats** ㄴ refers specifically to glycerol with 3 fatty acids ㄴ huge energy reserves for most organism ㄴ Fat storage in adipocytes Inuit have a greater proportion of subcutaneous fat compared with Europeans who tend to have more visceral adipose tissue \- beneficial in cold environments as subcutaneous fat has insulating properties  **Glycogen:** \- we don't have protein reserves \- Energy reserves Bacteria - oils and glycogen Fish - fats/oils and glycogen Plants - fats/oils and starch Fish do not control their body temperature, so in cold waters, fish would prefer oils (for a more fluid reserve)  Carbohydrates and lipids \- many functions in cell \- energy storage 4 Cal/g Simple to break down Slow to break down LipidsL 9 Cal/g Carbs and lipids recap