Amino acids fatty acids and sugars

Fatty acids

What are the building blocks of lipids?

Acetate

What is the starter molecule in fatty acid synthesis?

Malonate

What is the extender molecule in fatty acid synthesis?

7 cycles

How many cycles are involved in fatty acid synthesis?

It holds onto the growing chain and rotates it through active sites.

What role does the Acyl Carrier Protein (ACP) play in fatty acid synthesis?

They are crucial for various bodily functions and cannot be synthesized by the body.

What is the significance of essential fatty acids (EFAs)?

Triglycerides (triacylglycerols), cholesterol esters, and membrane lipids.

What are the three main classes of fatty acid storage molecules?

Triglycerides (triacylglycerols)

What is the primary storage form of fatty acids?

In the smooth endoplasmic reticulum (smooth ER)

Where are fatty acids primarily synthesized?

1g of triglyceride stores 6 times more energy than 1g of glycogen.

What is the energy storage efficiency of triglycerides compared to glycogen?

It describes the plasma membrane as a 2-D fluid where lipids and proteins can move laterally.

What is the fluid mosaic model?

They have hydrophilic (water-loving) head groups and hydrophobic (water-hating) fatty acid tails.

What characterizes the amphiphilicity of membrane lipids?

They favor a bilayer structure due to their cylindrical shape.

What is the shape of glycerophospholipids in water?

They protect the cell and are important in cell-cell contact.

What is the role of sphingolipids in the cell membrane?

They are microdomains in the membrane that organize signaling molecules.

What is the significance of lipid rafts?

Saturated fatty acids pack tightly, while unsaturated fatty acids create kinks, increasing fluidity.

What is the difference between saturated and unsaturated fatty acids in terms of membrane fluidity?

Glycerophospholipids, sphingolipids, and cholesterol.

What are the major classes of membrane lipids?

The distribution of lipid types differs between the inner and outer leaflets.

What is the asymmetry of the plasma membrane?

They introduce double bonds into fatty acids, creating unsaturated fatty acids.

What is the function of desaturases in fatty acid metabolism?

The carbonyl group is reduced to a hydroxyl group.

What happens during the ketoreduction step in fatty acid synthesis?

It stabilizes membrane fluidity and structure.

What is the role of cholesterol in the plasma membrane?

Approximately 5 nm (50 Ångstroms) thick.

What is the typical size of a membrane lipid bilayer?

They interact with the aqueous environment, forming a barrier to solute diffusion.

What is the significance of the polar head groups of membrane lipids?

They can rotate, flex, and diffuse laterally, but flip-flop movement is rare.

How do membrane lipids move within the bilayer?

Arachidonic acid is a polyunsaturated fatty acid important for signaling and is derived from linoleic acid.

What is arachidonic acid and how is it different from other fatty acids?

It provides essential lipids for membrane structure and energy storage.

What is the importance of fatty acid synthesis in cellular metabolism?

It acts as a signaling molecule and is involved in cell signaling pathways.

What is the role of phosphatidylinositol in the cell membrane?

Amino acids

What are the building blocks of proteins?

On the ribosome

Where are proteins polymerized?

An amino group, a carboxyl group, a hydrogen atom, and a variable side chain (R group)

What is the basic structure of an amino acid?

Primary, Secondary, Tertiary, and Quaternary

What are the four levels of protein structure?

Hydrogen bonds, Van der Waals interactions, disulfide bridges, and salt bridges

What stabilizes tertiary protein structure?

The sequence of amino acids in a protein

What is the primary structure of a protein?

A single amino acid change from Glutamic acid to Valine (E6V) in hemoglobin

What is a common cause of sickle cell anemia?

Alpha helix and beta-pleated sheet

What are the two main types of secondary protein structure?

By hydrogen bonds between C=O and N-H groups of the peptide bond, four amino acids apart

How is the alpha helix stabilized?

Adjacent beta-strands stabilized by hydrogen bonds between carbonyls and N-H groups

What characterizes the beta sheet structure?

The same types of interactions that stabilize tertiary structure, but between different polypeptide chains

What interactions stabilize quaternary protein structure?

They act as enzymes, form the cytoskeleton, and control nutrient influx and product efflux across membranes

What is the role of proteins in the cell?

mRNA is translated into protein by ribosomes

What is the significance of mRNA in protein synthesis?

Non-polar 'R' groups that are often buried internally or in lipid phases

What are hydrophobic side chains in amino acids?

Serine, Threonine, Cysteine, Tyrosine, Asparagine, Glutamine

Which amino acids have polar 'R' groups?

Amino acids with side chains that can form salt bridges and hydrogen bonds

What are charged 'R' groups in amino acids?

Aspartic acid (Asp) and Glutamic acid (Glu)

Name two negatively charged amino acids.

Lysine (Lys) and Arginine (Arg)

Name two positively charged amino acids.

A covalent bond formed between the amino group of one amino acid and the carboxyl group of another

What is a peptide bond?

They provide strong covalent bonds that stabilize protein structure

What is the role of disulfide bridges in proteins?

They contribute to the overall stability of the protein's 3D shape

What is the significance of Van der Waals interactions in protein structure?

It is formed by proteins and is involved in cell division

What is the function of the mitotic spindle?

They translate mRNA into proteins

What is the role of ribosomes in protein synthesis?

3.6 amino acids

What is the typical number of amino acids per turn in an alpha helix?

It has alternating 'R' groups that point above and below the flat sheet

What is the structural feature of a beta sheet?

They stabilize both secondary and tertiary structures

What is the importance of hydrogen bonds in protein structure?

It is the most abundant protein found in the extracellular matrix, connective tissue, and muscle

What is the function of collagen in the body?