BIO 181 chapter 3

c.amino acids

The monomers that make up proteins are called ________. a. nucleotides b. disaccharides c.amino acids d. chaperones

b.secondary

The α helix and the β-pleated sheet are part of which protein structure? a. primary b.secondary c.tertiary d.quaternary

The four types of RNA are messenger RNA, ribosomal RNA, transfer RNA, and microRNA. Messenger RNA carries the information from the DNA, rRNA associates with a set of proteins to form ribosomes, tRNA transfers the correct amino acid to the site of protein synthesis. microRNA regulates the availability of mRNA for translation.

What are the four types of RNA and how do they function?

DNA has a double-helix structure, Remains in the nucleus,Carries genetic information.RNA is usually single-stranded,Leaves the nucleus, and Involved in protein synthesis

What are the structural differences between RNA and DNA?

Glucose and galactose are aldoses. Fructose is a ketose.

What kind of sugars are these, aldose or ketose?

Adenine is larger than cytosine and will not be able to base pair properly with the guanine on the opposing strand. This will cause the DNA to bulge. DNA repair enzymes may recognize the bulge and replace the incorrect nucleotide.

A mutation occurs, and cytosine is replaced with adenine. What impact do you think this will have on the DNA structure?

c. deoxyribose, thymine, and a phosphate group

A nucleotide of DNA may contain ________. a. ribose, uracil, and a phosphate group b. deoxyribose, uracil, and a phosphate group c. deoxyribose, thymine, and a phosphate group d. ribose, thymine, and a phosphate group

d.all of the above

An example of a monosaccharide is ________. a.fructose b.glucose c.galactose d.all of the above

d. polysaccharides

Cellulose and starch are examples of: a. monosaccharides b. disaccharides c. lipids d. polysaccharides

c.water and polymers

Dehydration synthesis leads to formation of a.monomers b.polymers c.water and polymers d.none of the above

The sequence and number of amino acids in a polypeptide chain is its primary structure. The local folding of the polypeptide in some regions is the secondary structure of the protein.Some proteins are formed from multiple polypeptides, also known as subunits, and the interaction of these subunits forms the quaternary structure

Describe the differences in the four protein structures.

Glycogen and starch are polysaccharides. They are the storage form of glucose. Glycogen is stored in animals in the liver and in muscle cells, whereas starch is stored in the roots, seeds, and leaves of plants. Starch has two different forms, one unbranched (amylose) and one branched (amylopectin), whereas glycogen is a single type of a highly branched molecule.

Describe the similarities and differences between glycogen and starch.

a.hydrolysis

During the breakdown of polymers, which of the following reactions takes place? a.hydrolysis b.dehydration c.condensation d.covalent bond

Fat serves as a valuable way for animals to store energy. It can also provide insulation. Waxes can protect plant leaves and mammalian fur from getting wet. Phospholipids and steroids are important components of animal cell membranes

Explain at least three functions that lipids serve in plants and/or animals.

A change in gene sequence can lead to a different amino acid being added to a polypeptide chain instead of the normal one. This causes a change in protein structure and function

Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.

b. glycosidic; galactose

Lactose is a disaccharide formed by the formation of a ________ bond between glucose and ________. a. glycosidic; lactose b. glycosidic; galactose c. hydrogen; sucrose d. hydrogen; fructose

a.the plasma membrane of animal cells

Phospholipids are important components of ________. a.the plasma membrane of animal cells b.the ring structure of steroids c.the waxy covering on leaves d.the double bond in hydrocarbon chains

b.cellulose

Plant cell walls contain which of the following in abundance? a.starch b.cellulose c.glycogen d.lactose

d.they tend to dissolve in water easily

Saturated fats have all of the following characteristics except: a.they are solid at room temperature b.they have single bonds within the carbon chain c.they are usually obtained from animal sources d.they tend to dissolve in water easily

d.nucleotides

The building blocks of nucleic acids are ________. a.sugars b.nitrogenous bases c.peptides d.nucleotides

In a dehydration synthesis reaction, the hydrogen of one monomer combines with the hydroxyl group of another monomer, releasing a molecule of water. This creates an opening in the outer shells of atoms in the monomers, which can share electrons and form covalent bonds.

What role do electrons play in dehydration synthesis and hydrolysis?

Polar and charged amino acid residues are more likely to be found on the surface of soluble proteins where they can interact with water, and nonpolar are more likely to be found in the interior where they are sequestered from water.

Which categories of amino acid would you expect to find on the surface of a soluble protein, and which would you expect to find in the interior? What distribution of amino acids would you expect to find in a protein embedded in a lipid bilayer?

because they contain carbon.

Why are biological macromolecules considered organic?

Trans fats are created artificially when hydrogen gas is bubbled through oils to solidify them. Some restaurants are banning trans fats because they cause higher levels of LDL, or "bad"cholesterol.

Why have trans fats been banned from some restaurants? How are they created?

The β 1-4 glycosidic linkage in cellulose cannot be broken down by human digestive enzymes. Cellulases can break down cellulose into glucose monomers that can be used as an energy source by the animal.

Why is it impossible for humans to digest food that contains cellulose?