3 - Biological molecules Flashcards
stuff about water due to it having a hydrogen bond
it’s polar, meaning it’s a good solvent
unusually high boiling point
it’s less dense as a solid as it forms a tetrahedral arrangement
it has cohesive and adhesive properties leading to capillary action
it’s a coolant
very cool transport medium
speedrun carbs
carbs are sugars aka saccharides. monosaccharides is one unit. polysaccharides have many units of C6H12O6.
glucose
there are two types:
alpha - the OH is under in C1
beta - the OH is on top in C1
condensation reactions
when the OH on C1 and C4 react together to form a water and a polysaccharide, which also forms a 1,4 glycosidic bond
starch
starch is made from two polysaccharides:
amylose - formed by two alpha glucose
amylopectin - also formed by two alpha glucose but the glycosidic bond is on carbon 1 and 6
hydrolysis reactions
you need water to break a glycosidic bond - that’s what a hydrolysis reaction is: the opposite of a condensation reaction
cellulose
two beta glucose molecules tbh
triglycerides
one glycerol, three fatty acids that’s joined with an ester bond in a condensation reaction
you should know how it looks, if not i’m very disappointed in you and you should google it rn
phospholipid
a phosphate and two fatty acids
phosphate head is hydrophilic
tails are hydrophobic
structure of an amino acid
amine group
r- group
carboxyl group
google it fam
protein structure
primary - flat 2d
secondary - formed with hydrogen bonds (alpha helix/ beta pleated sheet)
tertiary - 3d, they have:
hydrogen bonds
hydrophobic/philic interactions
ionic bonds
disulphide binds
sugar phosphate backbone
phosphodiester bond on 5’ to phosphate to 3’ on a sugar where a base is connected on 1’
pyrimidines
has one carbon ring - thymine and cytosine
purines
had two carbon rings - adenine and guanine
base pairs
adenine + thymine - AT
guanine + cytosine - GC
how to make maltose, sucrose and lactose?
A glucose + A glucosse > Maltose
Fructose + glucose > sucrose (normal sugar) Galactose + glucose > lactose (milk sugar)
Which 2 enzymes are involved in DNA replication?
DNA helicase
Catalyses the breaking of hydrogen bonds between base pairs and the untwisting of the DNA helix
DNA polymerase
Catalyses the formation of phosphodiester bonds between nucleotides in the new DNA strand
Describe the process of semi conservative DNA replication.
- DNA helicase catalyses the splitting of hydrogen bonds and unwinding of the double helix structure
2.The 2 separate polynucleotide chains have exposed bases
3.Free nucleotide pairs complementarily bond to form hydrogen bonds
4.DNA polymerase catalyses the condensation of the new nucleotides to form phosphodiester bonds
- The new molecule twists to form a double helix
What is a codon?
Base triplet, 3 bases which code for an amino acid
What is a gene?
A section of DNA with a complete sequence of codons for an entire protein.
What is degenerate code?
Amino acids can be coded for by more than one codon.
Define transcription.
Conversion of genetic code to sequence of nucleotides in mRNA that leave the nucleus via nuclear pores
Describe the process of DNA transcription.
1.DNA helicase catalyses the breaking of hydrogen bonds between the bases
2.Free RNA nucleotides base pair to the template/antisense strand
3.Phosphodiester bonds from - catalysed by RNA polymerase
4.Transcription stops at the end of the gene - completed strand is mRNA
5.mRNA detaches from antisense and leaves via nuclear pores to ribosome
Describe the process of translation
1.mRNA binds to small subunit of ribosome
2.tRNA with a complementary anticodon binds to the start codon (AUG) in the large subunit - the amino acid is activated (using ATP)
3.Another tRNA enters the ribosome, and binds to the next mRNA codon
4.The two amino acids form peptide bonds and is catalysed by peptidyl transferase (part of rRNA)
5.The ribosome moves along the RNA, the first tRNA is released, the second tRNA becomes the first and another tRNA binds to the large subunit
