Proteins And Carbohydrates Flashcards
What is a carbohydrate?
Compounds made of oxygen, carbon and hydrogen
What are the 3 uses of carbohydrates?
1) source of energy
2) storage of energy
3)structural function - cellulose in cell walls to add structure and rigidity
What is the general formula for monosaccharides?
(CH20)n
What type of molecule is a protein?
Macromolecule
What differs in amino acids structures?
A side group -“R” group
By what reaction is a dipeptide formed?
A condensation reaction
What two atoms on successive amino acids does a peptide form between?
C-atom on one and N-atom on another
What is collagen an example of?
A fibrous protein
What are fibrous proteins’ function and how are their structures fit for this?
Structural functions - chains run parallel to one another so cross bridges form, keeping a very stable structuee
What type of protein is enzymes and haemoglobin an example of?
Globular proteins
What are globular proteins’ function?
Metabolic functions
What is the primary structure of a protein?
The sequence of amino acids with polypeptide bonds (determined by DNA)
What is the secondary structure of a protein?
The curling or folding of a polypeptide chain due to hydrogen bonding - making a 3D shape
What is the tertiary structure of a protein?
The twisting and folding of a polypeptide chain, making a more specific 3D structure due to disulfide, hydrogen and ionic bonds
What is the quaternary structure of a protein?
Multiple polypeptide chains with prosthetic (non-protein) groups added in
What provides indirect evidence for evolution?
The same 20 amino acids occur in all living organisms - all came from same DNA
What is the test for peptide bonds?
Biuret test
What do you add to the sample and what is a positive/ negative result for peptide bonds?
NaOH(aq) and CuSO4 (aq) at room temp.
Positive = purple
Negative = blue
What are the two secondary structures of a protein?
Alpha helix, Beta pleated sheets
What is the structure of the alpha helix?
A stable coil with hydrogen bonds keeping it stable
What is the structure of Beta pleated sheets?
Chains folding over themselves into Zig-Zag structure
What are the 2 noticeable properties of monosaccharides? ( AKA sugars)
They are soluble and sweet
What are the three most important hexose monosaccharides?
-Glucose
-Fructose
-Galactose
What are the 3 adapted properties of glucose?
-small - so easily transported in and out of cells through carrier proteins
-Soluble - easily transported around an organism
-Less reactive - breakdown must be catalysed and so controlled by enzymes
