Figure 1 shows the melting temperature vs chain length of stearic acid, i.e. octadecanoic acid. 90 - Stearic acid 70 60 - S0 - 40 30 Room temperature 20 10 -10 -20 4 6 8 10 12 14 16 18 20 22 24 Number of carbon atoms Figure 1 (i) What is the appearance of stearic acid at room temperature? (ii) Where would the melting temperatures of the following fatty acids, oleic acid (cis-9- Octadecenoic), linoleic acid (cis,cis-9,12-Octadecadienoic), and linolenic acid (All cis- 9,12,15-Octadecatrienoic), fall on the Figure 1? Plot and indicate their relative locations. Briefly explain why.

"Potassium Bromate (KBr03) is added to flour as a softener that strengthens the texture of bread. It can do this by forming disulfide bonds between two cysteine amino acids in a reaction similar to the chemical equation given below. The function of KBr03 is to remove the 2 electrons needed to form the disulfide bond as shown in the figure below. Each of the cysteine amino acids will be in a protein chain, so the reaction binds the two chains together, giving the dough cohesion. However, potassium bromate is a proven carcinogen and is only allowed in foods in the United States because bakers will add the right amount and correct It has been assumed to meet the temperature and cooking time conditions. " KBRO, + C,H¸NO,SH → KBr + H,O+C,H„N,O,S, Balance the reaction of potassium bromate (KBr03) with the cysteine molecule (C3H6 NO2 SH) by converting it into the reduced step matrix using the additive matrix method. (Kis the symbol of potassium in the question) (Homogeneous linear equation…

Identify the components of an amino acid in the following diagram. (a) ______________ (b) ______________ (c) ______________ (d) ______________

The figure below illustrates the molecular structures of two fatty acids. A B H₂C The structural formula of erucic acid and behenic acid с H₂C D erucic acid behenic acid Which of the following best explains why erucic acid is liquid at room temperature but behenic acid is solid at room temperature? O OH The presence of a double carbon to carbon bond in erucic acid prevents the molecule from packing closely together. The lack of any double carbon-carbon bonds in behenic acid causes the molecule to be come polar and therefore packed more tightly. The larger number of carbon atoms in erucic acid prevents the molecule from packing tightly together. OH The smaller number of carbon atoms in behenic acid creates stronger covalent bonds between the carbon atoms allowing for them to pack more tightly together.

Draw the structures of the amino acids formed at physiological pH when the tripeptide below is hydrolyzed. H H O H H O H H O | + || H -N N H HC. CH2 CH2 HC H₂C H₂C OH HC CH CH NH₂ Click and drag to start drawing a structure.

b) The likelihood of both triglycerides and phospholipids to behave as liquids at a given temperature is affected by their degree of saturation. Explain what saturation is and provide a biochemical explanation for why it affects the likelihood of a lipid to behave as a liquid at a given temperature. 5) a) Proteins have multiple "levels" of structural complexity. Match the type of chemical bond on the left with the level of protein structure that they are specifically involved in maintaining on the right. (Note that more than one letter may apply to each structural level and that each letter may be used more than once or not at all). a. disulphide bonds Tertiary structure b. hydrogen bonds Primary structure c. ionic bonds Quaternary structure d. peptide bonds Secondary structure