Enzymes
What is enzymes?
Biological catalysts which speed up reactions
What is genetic engineering?
It’s a process that uses laboratory-based technologies to alter the DNA makeup of an organism.
What is a genetic mutation?
A mutation is a random change in the nucleotide sequence of DNA or RNA.
What are the two main stages of protein synthesis?
The process is divided into transcription and translation.
What is the primary purpose of DNA replication?
It is the process by which a cell makes an exact copy of its DNA.
What is a catalysts?
A catalyst is a substance which can
speed up a reaction without becoming a
product.
How does CRISPR work?
Think of CRISPR as "molecular scissors." It uses a specific protein (Cas9) and a guide molecule to find a precise location in the DNA, cut it, and then allow the cell to repair that break—either by disabling a gene or inserting a new one.
What is the difference between a point mutation and a frameshift mutation?
A point mutation (substitution) affects only a single nucleotide, while a frameshift mutation (insertion or deletion) shifts the entire reading frame, often changing every amino acid that follows.
What happens during transcription and where does it occur?
In the nucleus, the DNA sequence of a gene is copied into a messenger RNA (mRNA) strand.
During which phase of the cell cycle does replication occur?
It takes place during the S phase (Synthesis phase) of interphase.
what do enzymes and protein have to do with each other?
Enzymes and a class of protein that act as a biological catalysts, while protein are a complex enzymes amino acid chain with a three-dimensional shape.
What are "GMOs"?
Genetically Modified Organisms (GMOs) are living things—usually plants or animals—whose genetic material has been artificially manipulated.
Why are some mutations called "silent"?
Silent mutations change the DNA sequence but do not change the resulting amino acid because the genetic code is redundant.
What is a codon?
A codon is a sequence of three nucleotides on an mRNA strand that codes for a specific amino acid.
Which enzyme is responsible for "unzipping" the DNA double helix?
DNA helicase breaks the hydrogen bonds between nitrogenous bases to separate the two strands.
Outline the role of the enzyme in the cell?
Enzymes enable reactions which would usually occur very slowly to happen at a much quicker rate, without being used up in the reaction themselves.
Can genetic engineering be used on humans?
Yes, primarily through gene therapy to treat diseases like sickle cell anemia or certain cancers. However, modifying "germline" cells (sperm, eggs, or embryos) is highly controversial because those changes would be passed down to future generations.
What is a mutagen?
A mutagen is an environmental factor, such as UV radiation or certain chemicals, that increases the frequency of mutations.
What is the role of tRNA in translation?
Transfer RNA (tRNA) carries the correct amino acids to the ribosome by matching its anticodon to the mRNA codon.
What does it mean that DNA replication is "semi-conservative"?
It means that each new DNA molecule consists of one original (parental) strand and one newly synthesized strand.
Distinguish between anabolic and catabolic enzymes?
Anabolic enzymes take small molecules and build larger ones, whereas catabolic enzymes take large molecules and break them into smaller ones.
What are the biggest risks?
The main concerns include unintended "off-target" effects (cutting the wrong part of the DNA), ecological imbalances (like "superweeds" that resist chemicals), and ethical dilemmas regarding the creation of "designer" organisms.
What is the difference between germline and somatic mutations?
Germline mutations occur in reproductive cells (eggs/sperm) and can be passed to offspring, whereas somatic mutations occur in body cells and are not inherited.
Where in the cell are proteins actually assembled?
Translation occurs at the ribosomes, which can be free-floating in the cytoplasm or attached to the rough ER.
What is the role of DNA polymerase?
This enzyme adds new complementary nucleotides to the growing DNA strand and proofreads the sequence to correct errors.