What Happens In Cell Flashcards
(16 cards)
What is a chromosome?
A long molecule of DNA. People have 46 chromosomes half from your father and half from your mother
What is a gene
A gene is a short section of DNA that codes for a specific characteristic such as eye colour
What is the shape of DNA?
A double helix
DNA is made of lots of small units called nucleotides. What are nucleotides made of?
A sugar, a phosphate and a base
What is complementary base pairing?
The two strands of DNA are held together by based bonding. Each base bonds to a specific other base. Adenine bonds with thymine. Cytosine bonds with guanine
What is mRNA?
mRNA is is a copy of DNA it is single strand and can leave the nucleus
What is transcription?
The process to make mRNA. The DNA around a gene unzips so that the strands are separated. One of the strands acts as a template. Complementary bases attach to the strand being copied this forms mRNA. The DNA zips itself back up.mRNA leaves the nucleus and travels into ribosomes
How are proteins made?
Proteins are made from amino acids. Different amino acids will form different proteins the order of nucleotides in the DNA determines the type and order of the amino acids
What is translation?
Once the mRNA is attached to a ribosome the ribosome reads the nucleotides on the mRNA in groups of three. These groups are called codons. Each codon codes for an amino acid. The ribosome adds more and more amino acids the amino acids join a chain this is a protein
What are enzymes?
Enzymes are made of protein they are biological catalysts they speed up a reaction without being used up themselves
What does it mean when enzymes are referred to as highly specific?
They only bind to one type of substrate molecule. The substrate must fit exactly into the active site
What is the lock and key hypothesis?
It compares enzymes and substrates to a lock and key only one substrate will fit into the enzyme
Give two examples of when enzymes are used?
In protein synthesis it builds larger molecules from smaller ones. In digestion they break down large molecules into smaller ones
How does temperature affect enzymes?
As temperature increases the enzymes and substrates move faster and collide more frequently. However at a certain temperature the enzymes become denatured
How does PH affect enzymes?
Each enzyme has its own optimal ph so the closer to the ph the faster the reaction
How does the substrate concentration or enzyme concentration?
The greater the concentration the faster the reaction up to a point when all enzymes are full or all substrates are being reacted
