Lipids and Carbs

The fat that serves as the main lipid storage molecule is a:

Triacylglycerol

• Also called triglycerides

What is triglycerides composed of

• 3 Fatty acids attached to a glycerol backbone

What are predominately used to form the Plasma membrane of cells

Phospholipids

What molecules are primarily stored in adipose tissue as stored energy

triglycerides

What does Saponification of lipids with fatty acids connected via an ester linkage include

• Triacylglycerols

• Sphingolipids

• Phospholipids

What is Saponification

• Esters are turned into soaps

• Converts a larger lipid molecule into the salts of its component fatty acids

Sphingolipids participate in:

Cell signaling and Apoptosis

• A type of lipid where fatty acids are attached to a sphingosine backbone

• Act as signal-transducing molecules

What is the role of Cholesterol in the plasma membrane

• Prevents lower temperatures from inhibiting fluidity

• At high temp —> prevents increase in fluidity

• At low temp —> Maintains membrane fluidity

What is the role of Cholesterol

• Production of steroid hormones

• Maintenance of cell membrane integrity

What are the properties of Unsaturated Fatty acids

• They have Kinks due to the presence of double bonds

• Increase membrane fluidity

What are the properties of Saturated Fatty acids

• No double bond

• Decrease membrane fluidity

What is the difference between long-chain fatty acids vs Short-chain fatty acids

• LC Fatty Acids: more rigid which makes the membrane less fluid

• SC Fatty Acids: Limited impact on membrane fluidity

What is the base molecule for steroid hormones

Cholesterol

• For hormones such as estrogen and testosterone.

Are steroid hormones lipid soluble or insoluble

Lipid Soluble

What about steroid hormones

They are peptide hormones, derived from Amino acids

What are Terpenes

• They are a class of unsaturated lipids

• Commonly found in plants

• Molecular formula (C5H8)n for n>1

What is the molecular formula for Isoprene

C5H8

What is the three precursor for prostaglandins?

• Arachidonic acids (AA)

• dihomo-y-linolenic acids(DGLA)

• eicosapentaenoic acids(EPA)

Describe prostaglandins?

• Group of lipids with hormone-like action that is produced in response to infection or tissue damage

What is a waxy substance often found in animals and vegetable fats

Stearic acid

Prostaglandins can be found as regulators of cell signaling in the:

• Cardiovascular + Respiratory + Urinary system

What dies Nucleotides contain

• 5 carbon sugar

• A phosphate group

• Nitrogenous base

What are the purines

Adenine and Guanine

What are the pyrimidine

• Cytosine

• Uracil

• Thymine

What nucleotides exist as Keto-enol tautomers?

Guanine, Uracil, Thymine

What nucleotides shift between amino form and imino form?

Adenine and cytosine

If adenine undergoes a tautomeric shift, it will bind to:

Cytosine

• Adenine would be unable to hydrogen bond with thymine

What is a tautomeric shift?

The spontaneous isomerization of a nitrogen base to an alternative hydrogen-bond form, possibly resulting in a mutation

The Chargraff’s rules state that:

DNA should have 1:1 ratio of purines to pyrimidines

What vitamin would result in precipitate formation when the same amount of Vitamin powder is added to carbon tetrachloride in a beaker

Vitamin B

What are the fat-soluble vitamins

A,D,E,K

• Have the capacity to be stored in the body for prolonged period

• Susceptible to toxicity risks

What are the water-soluble vitamins

B-complex and Vitamin C

• required for daily consumption as they are not stored in the body

What to know about Carbon tetrachloride (CCl4)

• Has a tetrahedral structure around a carbon atom

• Net-zero dipole moment

• Non-polar solcent

• Fat-soluble vitamins would dissolve in non-polar solvents and water would precipitate

Role of Sphingolipids

• Major structural component of the nervous system

• Involved in signal transmission and cell recognition

• Can be found as ceramide, ganglioside and cerebroside.

Sphingolipids can be found as

• ceramide

• ganglioside

• cerebroside.

Phospholipids vs Sphingolipids

What are the four interactions that help stabilize teh tertiary structure of a protein

• Ionic bonding

• Hydrogen bonding

• Disulfide linkages

• Dispersion forces

Describe hydrophobic interactions in the case of tertiary structure interaction

This is the non-polar amino acid side chain cluster together in the protein’s interior to avoid water, aiding folding and stability

Describe hydrogen bonds in the case of tertiary structure interaction

The peptide backbone and polar amino acid side chains form hydrogen bonds stabilizing secondary structures and folding patterns

Describe Ionic interactions(salt bridges) in the case of tertiary structure interaction

Attraction between oppositely charged amino acids chains leads to salt bridge formation, stabilizing the structure

Describe Disulfide bonds in the case of tertiary structure

Covalent bonds between sulfur atoms of cysteine residue form disulfide bridges, adding stability

Describe Van der waals interaction in the case of tertiary structure

Weak, attractibe forces between nonpolar molecules contribute to compact folding

What binds to the allosteric site independently from substrate attachment

Noncompetitive substrate