Lipids, Nucleic Acids & Proteins the ‘other’ fuel sources

Lipids water insoluble – hydrophobic long term NRG storage – adipose tissue TWICE as much NRG as carbs and proteins composed of: – CARBON – HYDROGEN – oxygen © 2012 Pearson Education, Inc.  NONPOLAR!!!

Lipids weird: – not huge molecules – not built from monomers big variations in: – structure – function (didn’t I just say that?) © 2012 Pearson Education, Inc.

Lipids Fats – glycerol + 3 fatty acids (FA) Phopholipids – glycerol + 2 FA + phosphate group (hey-aren’t they polar?) Steroids (aka. stereos) – ring structures built on cholesterol (evil or not? NOT!!) © 2012 Pearson Education, Inc.

FATS glycerol + 3 FA – each FA attached to glycerol through dehydration synthesis – each FA can be different from the others vary in length of carbon chain vary in numbers of double bonds vary in placement of double bonds aka. TRIGLYCERIDES © 2012 Pearson Education, Inc.

Figure 3.8B Fatty acid Glycerol p. 40

Figure 3.8C Fatty acids Glycerol p. 40

Fats carbon chains that have ALL single bonds SATURATED (as full of H as possible!) b/c straight chains they can pack together tend to be solid (at room temp)

Fats carbon chains that have one or more double bonds UNSATURATED (not as full of H as possible!) chains are kinked  can’t pack together too tightly tend to be liquid (at room temp)

Phospholipids glycerol backbone + 2 FA + phosphate group MAJOR component of ALL cells biggest constituent of the cell membrane © 2012 Pearson Education, Inc.

Phospholipids: cell membrane phospholipids cluster into a bilayer hydrophilic heads are in contact with – the water of the environment and – the internal part of the cell. hydrophobic tails band in the center of the bilayer.

Steroids based on structure of cholesterol four fused rings of carbon

Nucleic Acids storage, transmission & use of genetic information NRG transfer deoxyribonucleic acid: DNA ribonucleic acid: RNA monomers bonded to others to create polymers monomers = nucleotides

Nucleotides pentose sugar – ribose – Deoxyribose phosphate group nitrogenous base – adeninethymine (DNA only) – guaninecytosineuracil (RNA only)

Figure 3.15A Phosphate group Sugar Nitrogenous base (adenine)

3C 5C 3C 5C

Figure 3.15C Base pair A C T G C CG T A CG A T T A G C T A T A A T

DNA vs. RNA DNA deoxyribose sugar nitrogenous bases – adeninethymine – cytosineguanine double helix RNA ribose sugar nitrogenous bases – adenineuracil – cytosineguanine single stranded

DNA to RNA to proteins DNA contains genes: codes for proteins lives in the nucleus protein machinery is in the cytoplasm DNA transcribed into mRNA mRNA leaves nucleus mRNA is translated into proteins

DNA to RNA DNA monomers = nucleotides – language monomers = alphabet letters mRNA monomers = nucleotides transcribe DNA into mRNA – uses the same alphabet/same language

RNA to protein mRNA monomers = nucleotides protein monomers = amino acids information written in nucleotide language needs to be translated into amino acid language

Nucleotides & NRG Transfer Adenosine triphosphate (ATP) is a universal energy-carrying nucleotide found in all living organisms