Enzyme Function and Protein Synthesis Quiz

Enzymes

• Enzymes are globular proteins that act as biological catalysts, speeding up chemical reactions by lowering the activation energy.
• Enzymes have a specific three-dimensional shape with an active site, the location where a substrate (the molecule being acted on) binds.
• Enzyme-substrate specificity is the ability of an enzyme to bind only to specific substrates due to the complementary shape of the active site and the substrate.
• Enzyme activity is most effective at a specific temperature (optimum temperature). As temperature increases beyond the optimum, the enzyme structure denatures, and activity decreases.
• Enzyme activity is also optimal at a specific pH range. Deviations from the optimal pH cause enzyme denaturation, reducing activity.
• Substrate concentration initially increases enzyme activity, but once saturation is reached, further increases in substrate have no effect on the rate.

Harmless Skin Virus Fights Acne

• Acne is caused by clogged hair follicles.
• Propionibacterium acnes bacteria can contaminate clogged follicles, causing infection.
• Phages are viruses that share genetic material, including a common endolysin enzyme, that can destroy bacteria by breaking down their cell walls.
• Endolysin is a biological catalyst (enzyme).

The Evolution of Sick Humans - Enzymes

• Proteins are chains of amino acids.
• Enzymes are proteins that act as biological catalysts.
• The active site is the location on an enzyme where a substrate binds.
• Enzyme-substrate specificity describes how the shape of the active site precisely matches the shape of the substrate.
• Denaturation is a permanent change in the protein structure that occurs due to high temperatures or pH changes, causing a loss in biological activity of the enzyme.

Effects of Temperature, pH, and Substrate Concentration on Enzyme Activity

• Enzyme activity is most efficient at an optimum temperature.
• High temperatures cause enzyme denaturation.
• Each enzyme has an optimal pH range.
• Initial increases in substrate concentration increase enzyme activity up to a point where enzyme saturation is reached at which time further increases in substrate cause no change in activity.

Outline the Range of Functions of Proteins

• Enzymes (e.g., lactase breaks down lactose).
• Hormones (e.g., insulin regulates blood sugar).
• Cell receptors (e.g., insulin receptors in liver cells).
• Components of the immune system (e.g., antibodies).
• Structural components (e.g., collagen).

Outline the Organization of Human DNA

• Coding DNA contains instructions for protein synthesis.
• Non-coding DNA regulates gene expression.
• Junk DNA has no known function.

Fossil Record, Selective Breeding, and Homologous Structures

• Fossils are preserved remains or traces of ancient organisms.
• Fossil records provide evidence of evolutionary change.
• Fossil records show sequences of forms of life, including extinct species that are related to existing species.
• Fossils include impressions, organisms in amber, and pollen grains.
• Selective breeding demonstrates evolutionary change.
• Homologous structures (e.g., tetrapod forelimbs) suggest common ancestry.

Comparative Anatomy, Embryology, and DNA Sequence Comparisons

• Comparative anatomy studies similar structures in different species to determine evolutionary relationships.
• Comparative embryology determines if similar stages of development exist among species.
• DNA sequence comparisons determine similarities and differences to evaluate evolutionary relationships among species.

Evolution of Sick Humans Quiz 1 Review

• DNA Replication: enzymes use a template to generate new strands; nucleotides are incorporated following pairing rules
• Complementary bases: A with T, and C with G
• Gene definition: a segment of DNA that codes for a protein
• Gene locations: DNA replication in the nucleus, transcription in the nucleus, translation in the cytoplasm
• Transcription: DNA turns into mRNA
• Translation: mRNA turns into protein
• Codons: mRNA sequences of 3 nucleotides used to determine amino acid sequences

The Genetic Code

• Each three-base mRNA sequence (codon) specifies a particular amino acid. Codons determine the amino acid sequence for the protein to be constructed.
• The genetic code is the system that cells use to translate information in DNA/RNA into proteins.

Outline the process of translation leading to protein formation

• mRNA leaves the nucleus and binds to a ribosome.
• tRNA molecules bring amino acids to the ribosome.
• The anticodon sequence on tRNA binds to the complementary codon sequence on mRNA.
• Amino acids are linked to form a protein chain.
• Translation continues until a stop codon is reached, terminating protein synthesis.

Define mutation

• A gene mutation is a change in the DNA base sequence of a gene.

DNA (deoxyribonucleic acid)

• DNA is a molecule that stores genetic information.
• DNA is made up of subunits called nucleotides.
• A nucleotide consists of three parts: a phosphate group, a sugar (deoxyribose) and a nitrogenous base.

Explain how a DNA double helix is formed

• Two single strands of DNA join together.
• The bases (A, T, C, G) form hydrogen bonds pairing A to T, and C to G.
• The double helix twists into a spiral shape.

Define chromosome, gene, trait, and heredity

• Chromosome: a structure of DNA and protein that carries genetic information.
• Gene: a segment of DNA that codes for a particular protein.
• Trait: an observable characteristic of an organism.
• Heredity: passing of genetic information from parent to offspring.

Explain DNA replication

• Before cell division, DNA must be replicated to ensure each new cell receives a complete set of chromosomes.
• DNA strands unwind and separate.
• Enzymes use the separated strands as templates to create new strands.
• Complementary bases are incorporated (A-T and C-G) to generate new complementary strands.

Outline DNA transcription

• A single DNA strand is used as a template for mRNA synthesis.
• RNA nucleotides are bonded together by enzymes to form mRNA following the template strand nucleotide sequence.
• RNA nucleotides are similar to DNA, with uracil (U) replacing thymine (T).. 
• mRNA carries the genetic information from the nucleus to the cytoplasm for protein synthesis (translation).

This quiz tests your understanding of enzymes and protein synthesis, including enzyme activity, the effects of temperature and pH, and the roles of various types of RNA. Explore how enzymes function in biological systems and the process of forming proteins from genetic information.