Untitled Quiz

<p>Functioning as chemical messengers (D)</p> Signup and view all the answers

<p>Simple diffusion through lipid bilayer (B)</p> Signup and view all the answers

<p>Indicate the degree of unsaturation in fats and oils (B)</p> Signup and view all the answers

<p>High temperatures improve the extraction rate. (C)</p> Signup and view all the answers

<p>Cells shrink due to loss of water (D)</p> Signup and view all the answers

<p>Perform cyclooxygenase and reduce peroxide (C)</p> Signup and view all the answers

<p>PGE2 (C)</p> Signup and view all the answers

<p>They mediate inflammation and pain. (C)</p> Signup and view all the answers

<p>It inhibits the early step in prostaglandin synthesis. (B)</p> Signup and view all the answers

<p>They induce contraction of airway muscles. (C)</p> Signup and view all the answers

<p>Respiratory problems, such as asthma attacks. (C)</p> Signup and view all the answers

<p>A six-membered ring containing an ether (C)</p> Signup and view all the answers

<p>PGH synthase (A)</p> Signup and view all the answers

<p>The composition of fatty acids and temperature (A)</p> Signup and view all the answers

<p>They introduce kinks that lead to disorder in packing (A)</p> Signup and view all the answers

<p>Transition (melting) temperature (Tm) (B)</p> Signup and view all the answers

<p>Increase in fatty acid saturation (A)</p> Signup and view all the answers

<p>Lipid chains increase in disorder (A)</p> Signup and view all the answers

<p>By modifying the composition of fatty acids in their membranes (D)</p> Signup and view all the answers

<p>It transitions to a more ordered crystalline state (D)</p> Signup and view all the answers

<p>By incorporating more saturated fatty acids (A)</p> Signup and view all the answers

<p>Storage of metabolic energy (B)</p> Signup and view all the answers

<p>They are more reduced than carbohydrates (A)</p> Signup and view all the answers

<p>9 kcal/g (B)</p> Signup and view all the answers

<p>To prevent oxidation of double bonds (D)</p> Signup and view all the answers

<p>Triacylglycerols can store energy for significantly longer periods. (A)</p> Signup and view all the answers

<p>The carboxyl carbon (A)</p> Signup and view all the answers

<p>Omega-6 fatty acids (D)</p> Signup and view all the answers

<p>They can contain two or three different fatty acids. (A)</p> Signup and view all the answers

<p>They provide insulation and protection to body organs. (C)</p> Signup and view all the answers

<p>It is located between the 3rd and 4th carbons from the ω-end (A)</p> Signup and view all the answers

<p>Presence of highly unsaturated fatty acids from fish (B)</p> Signup and view all the answers

<p>They are released and oxidized to provide energy. (D)</p> Signup and view all the answers

<p>It suggests the storage efficiency of fats over carbohydrates. (D)</p> Signup and view all the answers

<p>Using Δ notation relative to the methyl end (B)</p> Signup and view all the answers

<p>Eicosapentaenoic acid (EPA) (B)</p> Signup and view all the answers

<p>Increased risk of heart disease (C)</p> Signup and view all the answers

<p>Phospholipids orient their polar heads towards the aqueous environment and hydrophobic tails away from it. (A)</p> Signup and view all the answers

<p>Bilayers (C)</p> Signup and view all the answers

<p>Steric effects from their two fatty acid chains. (C)</p> Signup and view all the answers

<p>Liposomes result from bilayers wrapping around to create a continuous surface. (D)</p> Signup and view all the answers

<p>Fatty acids begin to aggregate into micelles. (A)</p> Signup and view all the answers

<p>Phosphatidylcholine (A)</p> Signup and view all the answers

<p>They interact favorably with water. (A)</p> Signup and view all the answers

<p>Micelles (C)</p> Signup and view all the answers

Heterogeneous organic compounds primarily insoluble in water but soluble in organic solvents like ether and chloroform.

Lipids serve as energy storage molecules and chemical messengers in biological systems.

Lipids are insoluble in water, but dissolve in organic solvents.

Fats are a major form of stored energy in biological systems, releasing more energy than carbohydrates when fully broken down.

Lipids include fats, waxes, oils, hormones, and membrane components.

Lipids are a key component of cell membranes.

The structure of the membrane determines its function.

Lipids can be isolated from food sources like egg yolks.

The most abundant naturally occurring lipids, composed of three fatty acids and glycerol, commonly known as fats (solid) and oils (liquid).

Triacylglycerols accumulate in adipose tissue, serving as a means of storing fatty acids, especially in animals.

During starvation, lipases break down stored fats, releasing fatty acids that are oxidized for energy.

Besides energy storage, triacylglycerols provide insulation and protection for body organs.

Triacylglycerols serve as concentrated stores of metabolic energy, with a higher energy yield per gram compared to carbohydrates or proteins.

A triglyceride with two or three different fatty acids attached to the glycerol backbone.

A triglyceride with all three fatty acids being identical.

A triglyceride is comprised of glycerol (pink) with three fatty acids attached.

A system for naming fatty acids based on the position of double bonds relative to the carboxylic acid end (C-1).

A system for naming fatty acids based on the position of the first double bond relative to the methyl end (ω-end).

Fatty acids with the first double bond located three carbons from the methyl end.

Fatty acids with the first double bond located six carbons from the methyl end.

Fatty acids with more than one double bond.

An example of an omega-3 fatty acid.

Diseases related to the heart and blood vessels.

The functional group --COOH, characteristic of carboxylic acids.

Prostaglandins are categorized into two main groups: PGE (ether-soluble) and PGF (phosphate buffer-soluble). Each group contains subtypes like PGE1, PGE2, etc.

Prostaglandins act as chemical messengers in various tissues by regulating the production of cyclic AMP (cAMP), a key intracellular messenger.

PGE increases fatty acid levels by boosting cAMP synthesis. It plays a role in inflammation.

PGE2 causes blood vessel dilation, activates immune cells, and attracts macrophages to injury sites.

Macrophages, attracted by PGE2, contain hydrolytic enzymes that break down tissue at injury sites, leading to water influx and inflammation.

Prostaglandins are synthesized from arachidonic acid using an enzyme called PGH synthase. This enzyme has two functions: cyclooxygenase and peroxide reduction.

Aspirin inhibits the cyclooxygenase activity of PGH synthase, blocking the early steps of prostaglandin synthesis. This explains its anti-inflammatory effect.

Thromboxanes, another type of eicosanoid, contain a unique six-membered ring with an ether. Produced by platelets, they trigger blood clot formation.

Glycerophospholipids consist of a polar head group attached to a glycerol backbone. They have two fatty acid tails forming a nonpolar region.

Phospholipids spontaneously arrange themselves in a bilayer structure in water. Their polar heads face outward towards water, while their nonpolar tails face inward.

A spherical structure formed by a phospholipid bilayer that encloses an internal space. They are commonly used to deliver substances into cells.

A spherical structure formed by single-chain lipids, with their polar heads facing outward and their nonpolar tails clustered inward.

The concentration of single-chain lipids at which they begin to associate and form micelles.

A major component of most eukaryotic cell membranes, classified as a glycerophospholipid.

Another important glycerophospholipid, playing a role in cell structure and signaling.

Weak, non-covalent attractions between molecules, essential for stabilizing the structure of phospholipid bilayers.

The ease with which molecules can move within a membrane. It is influenced by factors such as the presence of unsaturated fatty acids, temperature, and the composition of the membrane.

Fatty acids with only single bonds between carbon atoms. They tend to pack tightly, making the membrane less fluid.

Fatty acids that contain double bonds between some of their carbon atoms. The double bonds cause kinks in the fatty acid chain, making them pack less tightly and increasing membrane fluidity.

The temperature at which a membrane transitions from a more ordered, solid-like state to a more disordered, fluid state.

At higher temperatures, membranes become more fluid as the lipid molecules move more freely. Conversely, at lower temperatures, membranes become more rigid as the molecules pack more tightly.

Organisms can adjust the composition of their membranes by altering the types and amounts of fatty acids present. For example, bacteria and cold-blooded animals increase the proportion of unsaturated fatty acids in their membranes at lower temperatures to maintain fluidity.

In the crystalline state, fatty acid tails are fully extended and tightly packed, resulting in a rigid membrane. In the liquid crystal state, the tails become more disordered, and the membrane gains fluidity.

Longer fatty acid chains tend to pack more tightly, making the membrane less fluid. This is because they have more surface area for van der Waals interactions.