1 - Biological Molecules Flashcards
Why is water polar?
Oxygen is ẟ negative and hydrogen is ẟ positive
Bond that attracts water molecules to eachother
Hydrogen
Give 5 properties of water
High SHC Less dense as solid Cohesion - surface tension Adhesion Universal solvent
How to test for reducing sugars
Equal volume of Benedict’s and heat
+ = blue to red
How to test for reducing sugars
Boil with HCL and add Benedict’s
+ = blue to red
Test for starch
Add a few drops of iodine
+ = orange to black
Test for proteins
Equal volume of Biuret A and B
+ = blue to violet
Test for lipids
Add alcohol and water, shake
+ = white emulsion forms on top
Define macronutrient
Nutrients that are needed in large amounts and provide body with energy
4 examples of macronutrients
Carbohydrates
Lipids
Proteins
Water (but no calories)
Define micronutrients
Nutrients that are needed in small amounts and important for normal functioning of the body
4 examples of micronutrients
Hydrogen ions (pH) Iron ions (haemoglobin) Sodium ions (AA, CNS) Phosphate ions (DNA and ATP
Define organic
Contains carbon
Name the monomer of carbohydrates
Glucose
Name the di-saccharides of carbohydrates
Sucrose, maltose
Name the polysaccharides of carbohydrates
Starch, cellulose, glycogen
Name 3 monosaccharides
Glucose, fructose, galactose
Two types of glucose
Alpha and Beta
Alpha Beta glucose difference
Alpha - H Beta - OH
OH H
Bond in fructose
Carbon 2 and Carbon 5
Name 3 disaccharides
Maltose, sucrose, lactose
……………+……………= maltose
Alpha glucose + alpha glucose
……………+……………= sucorse
Alpha glucose + beta fructose
……………+……………= galactose
Alpha glucose + galactose
What bond connects two glucose in maltose
———–o—————
Alpha 1-4 glyosidic bond
What reaction bonds the glucose together
Condensation
Opposite of condensation reaction
Hydrolysis
What is also formed in a condensation reaction
Water
What is starch made of?
Amylose and amylopectin
What is starch
Energy store in plants
Why does iodine test for starch?
Iodine gets trapped in helix of amylose
What is amylopectin? Bond?
Polymer of alpha glucose
Alpha 1-6 glyosidic bond
What feature does amylopectin have?
Side branches
What is glycogen?
Immediate energy store in animals
Bond in glycogen
Alpha 1-4 and Alpha 1-6 glyosidic bond
Adaptation of glycogen
Big SA so release glucose from every branch by breaking it
What is cellulose of polymer of?
Beta glucose
Bond in cellulose
Beta 1-4 glyosidic bond
Why is the structure of cellulose weird?
Every second glucose flips 180o to form parallel chains
Three uses for lipids
Insulation, waterproof, protection
3 differences between fats and oils
Fats - animals, solid, saturated
Oils - plants, liquid, unsaturated
Is C=C saturated or unsaturated?
Unsaturated
Is c-c-c-c-c- saturated or unsaturated?
Saturated
What are lipids made of?
Glycerol and fatty acids
Draw glycerol
H H H
H-C-C-C-H
H H H
O O O
Draw a fatty acid
H H H H
O= C - C - C - C - C -H
OH H H H H
Three groups in a fatty acid
Carboxyl (COOH)
Methyl (CH3)
Hydro-carbon chain
Bond in a triglyceride that connects glycerol to fatty acid?
Ester
Difference between triglyceride and phospholipids?
In a phospholipid, one of the FA is replaced by a phosphate group
What is in a phospholipid?
Polar?
Phosphate head (polar) Glycerol 2 FA (non-polar)
How many different AA are there?
20
Draw a amino acid?
R
COOH - C - NH2
H
3 groups in an amino acid
Carboxyl group (COOH) R group Amino group (NH2)
4 different types of r group
Acidic
Basic
Polar
Neutral
What is a dipeptide
Two AA bonded together
Bond in a dipeptide
Peptide
Name the 5 structures a protein can be in
Primary, secondary, tertiary, quaternary, conjugated
Describe the primary structure
1° - order and number of amino acids in a polypeptide chain. DNA sets this order
Bonds in primary structure
Peptide
Describe the secondary structure
Alpha helix and beta pleated sheets
Two primary together
Bonds in secondary structure
Hydrogen and peptide
Describe the tertiary structure
Globular shape and bonding between r groups
Determine overall shape
Bonds in tertiary structure
Hydrophobic interactions - non-polar r groups
Hydrogen bonds - r group
Ionic bonds - acidic and basic r groups
Disulphide ridges - sulphide r group (covalent bonds)
Describe the quaternary structure
More than one polypeptide chain. E.g. haemoglobin
Bonds in quaternary structure (4 and where found)
Hydrophobic interactions - non-polar r groups
Hydrogen bonds - r group
Ionic bonds - acidic and basic r groups
Disulphide ridges - sulphide r group (covalent bonds)
Describe the conjugated structure
A non-protein molecule is attached and is inorganic
Define enzyme
A biological catalyst that lowers the activation energy of a reaction
Describe induced fit
Substrate enters active site forming an enzyme-substrate complex (not complementary)
Active site changes shape which puts pressure on bonds in substrate
Lower activation energy
5 things that impact rate of enzyme catalysed reactions
Temperature pH Enzyme concentration Substrate concentration Inhibitors
Name the 2 types of inhibitor
Competitive and non-competitive
How does temperature impact the rate of an enzyme catalysed reaction
More kinetic energy = more collisions =more ES complexes = higher rate
Pass optimum temp then denature (hydrogen bonds break = lose tertiary structure = no complementary )
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How does pH impact the rate of an enzyme catalysed reaction
Move away from optimum pH (Hydrogen concentration changes) so ionic bonds break so active site isn't complementary so no ES complex /\ / \ / \ / \
How does enzyme concentration impact the rate of an enzyme catalysed reaction
Directly proportional to rate
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How does substrate concentration impact the rate of an enzyme catalysed reaction
Enzyme becomes limiting factor
x2 conc. = x2 rate
All active sites are occupied so enzyme is saturated
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
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/How do competitive inhibitors impact the rate of an enzyme catalysed reaction
Molecule with similar shape to substrate binds to active site
Low sub con. = low rate
Will reach maximum rate
How do non-competitive inhibitors impact the rate of an enzyme catalysed reaction
Attaches to enzyme (not AS)
Changes bonding and AS so not complementary to substrate
Doesn’t reach maximum rate
Give 5 characteristics of Globular proteins
Transport (hormones) Lightly folded pp chains Soluble Haemoglobin Compact and spherical
Give the two types of proteins
Globular and Fibrous
Give 5 characteristics of Fibrous proteins
Structural and strength Parallel pp chains Long and narrow Insoluble in water Collagen
Describe haemoglobin (3)
Globular protein
4pp chains
2 alpha helixes and 2 beta pleated sheets
Describe collagen
Fibrous protein
3 pp chains and unbranched
What does ATP stand for?
Adenosine triphosphate
Describe structure of ATP
3 phosphate circles
Ribose pentagon
Rectangle nitrogenous base (Adenine)
What does ATP turn into to release energy?
Full name
ADP (Adenosine diphosphate) and Pi (inorganic phosphate)
4 uses of ATP
Active transport
CNS
Muscle contraction
Protein synthesis
1 glucose molecule = ….. mole of ATP
38
Explain how cellulose molecules are adapted for their function in plant cells (3)
- Long and straight chains;
- Become linked together by many hydrogen bonds to form fibrils;
- Provide strength (to cell wall);
Difference between glycogen and starch
Starch - energy source in plants
Glycogen - energy source in animals
