Biochemistry Term-2 Review

Fill-in-the-blank flashcards covering carbohydrates, lipids, proteins, and nucleic acids for the Term-2 biochemistry quiz.

The general molecular formula for carbohydrates is __.

(CH2O)n, where n ≥ 3

Glucose, fructose, and galactose are examples of __.

monosaccharides

A disaccharide is made of __ monosaccharides.

two

The bond that links monosaccharides together in polysaccharides is called a __ bond.

glycosidic

The polysaccharide used by plants for energy storage is __.

starch

Hydrolysis of starch releases the monomer __ for fuel.

glucose

The disaccharide composed of glucose + fructose is __.

sucrose

Maltose consists of two __ molecules.

glucose

Lactose is made of galactose and __.

glucose

During polysaccharide formation, water is removed in a process known as __.

dehydration

Lipids are insoluble in water but soluble in organic solvents such as __.

methanol or ethanol

The three major classes of lipids are fats/oils, phospholipids, and __.

sterols (steroids)

Fats and oils are the principal __ forms of energy in many organisms.

stored

Phospholipids form the basic structure of the __ membrane.

biological cell

Sterols such as cholesterol function as membrane reinforcers and __ molecules.

signalling (hormones)

A fat molecule is formed from glycerol and __ fatty acids.

three

The reaction that joins glycerol to fatty acids in fats is a __ reaction.

dehydration (ester linkage type)

Animal fats are richer in __ fatty acids and are solid at room temperature.

saturated

Vegetable oils contain more __ fatty acids and are liquid at room temperature.

unsaturated

Trans fats raise __ cholesterol and lower HDL cholesterol.

LDL ("bad")

Proteins are polymers of __.

amino acids

All common amino acids (except proline) have a hydrogen, amino group, and __ group attached to the α-carbon.

carboxyl

The simplest amino acid is __.

glycine

A peptide bond is also called an __ linkage.

amide

Removal of water to join two amino acids forms a __.

dipeptide

The linear sequence of amino acids in a protein is its __ structure.

primary

Regular folding such as α-helices and β-sheets constitutes __ structure.

secondary

The overall three-dimensional shape of a single polypeptide is its __ structure.

tertiary

The assembly of multiple polypeptide subunits into one protein is the __ structure.

quaternary

There are __ common amino acids found in proteins.

20

Alanine has the three-letter abbreviation Ala and the one-letter symbol __.

A

Amino acids with aromatic R groups belong to the class called __ R groups.

aromatic

DNA stands for __ acid.

deoxyribonucleic

RNA is typically __ stranded, whereas DNA is double stranded.

single

A nucleotide contains a phosphate, a pentose sugar, and a __ base.

nitrogenous

The pentose sugar in DNA is __.

deoxyribose

In DNA, the base adenine pairs with __.

thymine

In RNA, uracil replaces the DNA base __.

thymine

Purines have two rings and include adenine and __.

guanine

Messenger RNA carries the genetic code from DNA in a process called __.

transcription

Transfer RNA delivers __ acids to the ribosome.

amino

The double helix of DNA is stabilised primarily by __ bonding between bases.

hydrogen

A segment of DNA that codes for a functional product is called a __.

gene

A codon is a sequence of __ nucleotides that specifies an amino acid.

three

Of the 64 possible codons, __ code for amino acids.

61