Finals Biochem

Nucleic Acid

Nucleic Acid

Molecules discovered by Friedrich Miescher in 1869, they are polymers.

Nucleotides

Building blocks of nucleic acids, composed of pentose sugar, base, and phosphate.

Pyrimidine

One of the five nitrogen bases that are components of nucleotides.

Purine

One of the five nitrogen bases that are components of nucleotides.

Phosphate

Derived from phosphoric acid, it forms the phosphate group in nucleotides.

Nucleoside

Formed by the condensation of sugar and base, it is a subunit of nucleotides.

Nucleotide

Formed by the addition of a phosphate group to a nucleoside, it is the complete unit of nucleic acids.

Deoxyribose Acid

The sugar component of DNA, forming the backbone of the double helix structure.

Complementary Bases

Pair of bases in nucleic acid structure that bind together (A-T, G-C in DNA).

DNA Replication

Process where DNA molecules produce duplicates of themselves.

DNA Helicase

Enzymes responsible for unwinding DNA during replication.

Okazaki Fragments

Short segments of DNA formed during replication on the lagging strand.

DNA Ligase

Enzyme used to connect Okazaki fragments during replication.

Leading Strand

Strand of DNA that grows continuously during replication.

Lagging Strand

Strand of DNA that grows in segments during replication.

DNA Polymerase

Enzyme responsible for synthesizing the daughter strand during replication.

Chromosomes

DNA bound to proteins, containing genetic material.

Homologous

Pair of chromosomes that have the same genes at the same loci.

Ribonucleic Acid (RNA)

Single-stranded molecule involved in protein synthesis.

Messenger RNA (mRNA)

Carries instructions for protein synthesis from DNA to ribosomes.

Transfer RNA (tRNA)

Delivers amino acids to ribosomes during protein synthesis.

Transcription

Process where DNA directs the synthesis of RNA.

Gene

Base sequence in DNA that codes for the production of RNA.

Genome

All the genetic material contained in chromosomes.

Exon

Gene segment that conveys genetic information.

Intron

Gene segment that does not convey genetic information.

Splicing

Process of removing introns from hnRNA to form mRNA.

Codon

Three-nucleotide sequence in mRNA that codes for a specific amino acid.

Genetic Code

Assignment of 64 mRNA codons to specific amino acids.

Anticodon

Sequence of RNA that is complementary to a codon.

Translation

Process where mRNA codons are deciphered and protein molecules are synthesized.

Translocation

Movement of a codon down the mRNA during translation.

Activation of tRNA

Process where amino acid interacts with an activator to form an energetic complex.

Initiation

Process where mRNA attaches to the surface of ribosomes during translation.

Elongation

Process where tRNA anticodon binds with mRNA codon during translation.

Termination

Process where anticodons bind and protein synthesis stops during translation.

Post-Translation

Process where proteins acquire their final shape after translation.

Mutation

Error in the base sequence of a gene.

Point Mutation

Mutation where one base in the DNA sequence is replaced.

DNA Sequencing

Determining the base sequence in a DNA molecule.

Digestion

The process of changing food into simple absorbable substances.

Digestive enzymes

Enzymes that break down food into smaller molecules during digestion.

Vitamins and minerals

Nutrients that are released during digestion.

Amylase

An enzyme that breaks down carbohydrates.

Protease

An enzyme that breaks down proteins.

Lipase

An enzyme that breaks down fats.

Salivary amylase/ptyalin

An enzyme produced in the mouth that breaks down starch into dextrin and maltose.

Pancreatic amylase

An enzyme secreted by the pancreas into the small intestine that breaks down starch.

Invertase

An enzyme that catalyzes the hydrolysis of sucrose into fructose and glucose.

Pepsinogen

An inactive enzyme that is activated by stomach acid into protease pepsin, breaking down polypeptides into fragments.

Peptidase

An enzyme from the goblet cells of the small intestine that breaks down peptides into amino acids.

Chymotrypsinogen

An inactive enzyme that gets activated in the digestive tract and turns into chymotrypsin, breaking down proteins.

Gastric lipase

An enzyme from the stomach that breaks down short and medium-chain triacylglycerols.

Pancreatic lipase

An enzyme from the pancreas that digests triacylglycerols in the gastrointestinal tract.

Ribonuclease (RNase)

An enzyme that catalyzes the degradation of RNA into smaller components.

Deoxyribonuclease (DNase)

An enzyme from the pancreas that breaks down DNA.

Absorption

The process by which molecules are taken up by the epithelial cells of the intestinal villi.

Active transport

A mechanism of absorption where molecules move against their concentration gradient with the help of transport proteins.

Passive diffusion

A mechanism of absorption where molecules move along their concentration gradient.

Facilitated diffusion

A mechanism of absorption where molecules move across the membrane with the help of integral membrane proteins.

Co-transport

A mechanism of absorption where molecules are transported together with another molecule.

Endocytosis

The process of substances being taken into the cell through vesicles.

Exocytosis

The process of materials being released out of the cell.

Metabolism

The sum total of all biochemical reactions in a living organism.

Catabolism

Metabolic reactions where large molecules are broken down into smaller ones, usually releasing energy.

Anabolism

Metabolic reactions where small molecules are joined together to form larger ones, usually requiring energy.

Metabolic pathway

A series of consecutive biochemical reactions used to convert a starting material into an end product.

Adenosine phosphates

Important molecules in metabolism, including adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP).

Phosphoryl group

The functional group derived from a phosphate ion that is part of another molecule.

FAD/FADH2

Flavin adenine dinucleotide, a coenzyme involved in metabolic redox reactions.

NAD+/NADH

Nicotinamide adenine dinucleotide, another coenzyme involved in metabolic redox pathways.

Coenzyme A

A coenzyme derived from the B vitamin pantothenic acid.

Acetyl group

The portion of an acetic acid molecule that remains after the removal of the -OH group.

Acetyl CoA

A compound formed by the bonding of an acetyl group to Coenzyme A.

High-energy compound

A compound that has a greater free energy of hydrolysis than a typical compound, often due to strained bonds.

Stomach Digestion

The process of protein digestion that occurs in the stomach, involving denaturation and hydrolysis of proteins.

Denaturation

The process in which proteins lose their structure and function due to changes in pH or temperature.

Hydrolysis

The process of breaking down proteins into smaller polypeptides or amino acids by adding water molecules.

Pepsin

An enzyme found in gastric juice that hydrolyzes peptide bonds in proteins, resulting in the formation of polypeptides.

Small Intestine Digestion

The continuation of protein digestion in the small intestine, where pancreatic enzymes attack peptide bonds.

Pancreatic Juice

A secretion from the pancreas that contains enzymes such as trypsin, chymotrypsin, and carboxypeptidase, which aid in protein digestion.

Aminopeptidase

An enzyme produced by intestinal mucosal cells that attacks peptide bonds, further breaking down polypeptides.

Proteolytic Enzymes

Enzymes involved in the digestion of proteins, produced as inactive zymogens initially.

Amino Acid Pool

The total supply of free amino acids in the body, derived from dietary protein, protein turnover, and liver biosynthesis.

Protein Turnover

The continuous process of protein degradation and resynthesis in the body, responding to factors like disease, injury, and normal wear and tear.

Nitrogen Balance

The balance between nitrogen intake (from dietary proteins) and nitrogen excretion in waste, indicating the overall protein status in the body.

Negative Nitrogen Balance

A state in which protein degradation exceeds synthesis, often associated with tissue wasting.

Positive Nitrogen Balance

A state in which protein synthesis exceeds catabolism, observed during growth, pregnancy, and recovery from illnesses.

Utilization of Amino Acids

The various ways in which amino acids from the amino acid pool are used, including protein synthesis, synthesis of nonprotein nitrogen-containing compounds, synthesis of nonessential amino acids, and production of energy.

Transamination

The process of transferring the amino group from an α-amino acid to an α-keto acid, resulting in the formation of a new amino acid.

Oxidative Deamination

The process of removing the amino group from an amino acid, resulting in the formation of ammonia and a keto acid.

Nucleic Acid

Molecules discovered by Friedrich Miescher in 1869, polymers composed of nucleotides.

Nucleotides

Building blocks of nucleic acids, composed of pentose sugar, base, and phosphate.

Pyrimidine

One of the five nitrogen bases in nucleotides, includes thymine, cytosine, and uracil.

Purine

One of the five nitrogen bases in nucleotides, includes adenine and guanine.

Phosphate

Derived from phosphoric acid, forms hydrogen phosphate ion under certain pH conditions.

Nucleotide Formation

Process of forming nucleotides, involves condensation and attachment of base and sugar through phosphate-ester.

Deoxyribose Acid

Sugar component of DNA, forms the backbone of the DNA double helix.

Complementary Bases

Pair of bases in nucleic acid structure, such as adenine with thymine or cytosine with guanine.

DNA Replication

Process of producing duplicates of DNA molecules.