Biology 20 IB - Unit C: Biochemistry and Enzymes

Macromolecules

Large, complex organic molecules

What are the 4 major groups under micromolecules?

Carbohydrates, lipids, proteins, and nucleic acids each with their own smaller subunits

What can water help?

• Universal solvent

• Regulates body temp. and temp.

• Increases cell permeability

• Cleans and lubricates tissues

• Supports/protects organs

• More dense than fat

• High specific heat capacity

Organic

Produced by biotic things and have a carbon backbone attached to hydrogens. Has strong covalent bonds and carbon chains.

Inorganic

Formed by abiotic things and doesn’t contain a hydrogen with a carbon, sometimes it contains just carbons. But no carbon chains.

Examples of organic substances

Methane, ATP, ethanol

Examples of inorganic substances

Carbon, carbon dioxide, carbon monoxide

Polymer

Macromolecules (or monomers) made up of repeating units

Ex. natural (DNA, RNA, proteins) synthetic (plastics)

Monomer

Small molecules that bond together to form more complex structures (polymers)

Polymerization

The process of joining monomers together; the process of creating polymers. Doesn’t need to release water.

What are polymers and monomers called in carbohydrates?

Polysaccharides and monosaccharides

Dehydration synthesis

Happens between 2 monomers, a hydroxide and a hydrogen molecule combine to form water (byproduct)

Condensation reaction

The loss of water molecules when dehydration synthesis happens

Hydrolysis

The breakdown of macromolecules using water

Carbohydrates

Contains carbon, hydrogen, and oxygen in different proportions and can be classified as simple sugars (monosaccharides + disaccharides) or complex sugars (polysaccharides). Identified with an -ose ending.

What is the main function of carbohydrates?

Main function is energy

Monosaccharide (1 monomer)

Used for energy and create ATP and RNA structures

eg. glucose, fructose, ribose

Disaccharide (2 monomers)

Found in grains, common sugars, and milk sugars and provides energy

eg. sucrose, maltose, lactose

Polysaccharide (3+ monomers)

Proform energy storage or structural support

eg. starch, cellulose (has FIBER) , plant fibers (linen, cotten)

Isomers

Molecules that have the same formula but different structures

eg. sugers are named based on how many carbons they have (n=3 - triose)

Cellulose

A polysaccharide that makes up the cell wall and formed through dehydration synthesis (2000 glucose units). Cannot be digested but it’s an important fibre in our diets.

Why can’t humans digest cellulose?

Humans lack an enzyme called cellulase, which cows and goats have

Where and how much of 50% organic carbon is tied up?

Tied up in cellulose and trees create carbon sinks

Structure of cellulose

A “straight chain” composition with beta-glucose monomers (hydroxide alternates up and down)

Glycogen

A polysaccharides that acts like a short term energy storage units in ANIMALS and joined by dehydration synthesis

The role of glycogen in humans

Produced + stored in liver/muscles after a meal. Have energy between meals :)

Individual sugar units are arranged determines their ____.

Shape and function

What happens when the shape is coiled and branched?

Easy storage and quick hydrolysis = access energy fast

What are 2 tests for testing carbohydrates?

Benedict’s Test + Iodine Test

Reducing sugars

A reducing agent (releases an electron to another molecule); has aldose or ketone

Lipids

Consists of glycerol (3-carbon chain) and fatty acids; also known as fats (in animals)/oils (in plants)

What are functions of lipids?

• Insoluble in water (floats)

• Storage of energy when glycogen is low

• Cushions organs

• Carries fat-soluble vitamins

• Makes sex hormones

• Insolation of body

• MAY increase buoyancy

Where do fats and oils come from?

Fats come from animal origin while oils come from plant origin

Triglyceride

Store unused calories, provide energy, and insolation for animals

eg. fish oil, animal fats, butter

Phospholipid (bilayer)

Forms a membrane that separates a cell from the internal environment and controls the movement of cells

eg. phosphotidylendine

Waxes

Forms a hydrophobic coating to protect water and reduce water loss

eg. protective coating on plants + fruits, cutin (cuticle)

Steroids

Forms sex hormones, helps energy metabolism

eg. anabolic steroids, estrogen, testosterone

Hypertonic

High concentration on the outside and water moves out of the cell making it shrivel

Istomic

There is equal solute inside and outside

Hypotonic

Higher solute inside and water will move inside the cell causing it to swell

Amphipathic molecule

A molecule that has polar and non-polar parts

eg. phospholipids

What fat do we obtain for our bodies?

Triglycerides/neutral fat (non-polar); obtain through diet

How are triglycerides formed?

1 glycerol (has to be the same) + 3 fatty acids (can have different formations) —(dehydration synthesis)—> 1 triglyceride + 3H2O

Adipose tissue

Body fats that are found all over the body and used for long term storage

Subcutaneous fat

Fat under the skin

Visceral fat

Fat around internal organs

Saturated fats

Has no double covalent bonds between carbon molecules to have as much hydrogen ions → why it’s harder to digest (solid); animal fatty acids

Unsaturated fats

Has 1+ covalent bonds between carbons → why they are easier to digest (liquid); plant fatty acids

Are more double bonds healthier in fats?

Yes because it’s easier to digest and they are mostly in liquid form

What do monounsaturated and polyunsaturated fats build?

These fats can build tissue and neurons

Phospholipids

Lipids that make up the cell membrane (bi-layer) and have different properties on each side

Do waxes have caloric value?

Waxes don’t have caloric value!

What are 3 types of lipid tests?

Emulsion, transparency, and Sudan 3 test

Emulsion test (qualitative test)

Tests to see if there is fat (shown as a white, milky substance)

Transparency test

Tests for lipids by penetrating the paper, making it appear translucent

Sudan 3 test

Tests for fats → if there is a presence of fats, it will turn bright red (has been banned for hazardous reasons)

Why do we need fats?

Fats have double the amount of energy than carbohydrates and are a back up energy for our bodies. But too much isn’t good.

Arteriosclerosis

The hardening of arteries → leads to increased blood pressure

Atherosclerosis

Lipid clinging on to the artery inner walls and creating a plaque (endothelial cells); lipid accumulation

What makes cholesterol?

Steroids

Cholesterol

A waxy, fat-like substance that makes structures like cell membranes

High density lipoprotein (HDL)

Good cholesterol that is responsible for reducing LDL → takes the LDL to the liver and gets turned into bile

Low density lipoprotein (LDL)

Bad cholesterol that can accumulate and create high blood pressure

Prosthetic

Attachment to a molecule

Proteins

Formed from amino acids that are put into long chains and are organized determined by the R group

R group

A group of 1+ atom(s) that decides the identity and shape. Distinguishes the 20+ types of protein.

What are proteins made of?

C,H,O,N (separates proteins from fats + carbs), and sometimes S

Peptide bonding

How individual amino acids are connected to each other

Dipeptide

2 amino acids connected together

Polypeptide

A molecule that has between 3 - 300 amino acids

How many amino acids does protein have?

300+ amino acids

How much protein can the human body synthesize and where to get them?

The human body can synthesize 11 proteins (out of 20) and the others are from our diet

eg. eggs (animal meats), peas, nuts, beans

Biuret Test

Tells us if there are proteins in substance by changing from blue to purple

The 4 forms of what protein can take

Linear, spiral/pleated, folded spiral/pleats, and folded spirals

Quaternary

A combo of 2+ forms that protein can take

Denaturation

Temp. change in protein shape from heat, pH, or chemicals. Can return to the original shape by removing the factor.

Coagulation

Permanent change in protein shape by heat, pH, or chemicals.

Deamination

Removal of amino acids from the protein/polypeptide chain.

Nucleic acids

Makes up DNA and RNA; contains phosphate, sugar, and nitrogen base.

Monomers of nucleic acids

Nucleotide → adenine, cytosine, guanine, and thymine (each are made of a 5-carbon sugar, phosphate molecule, and a nitrogen base)

DNA (Deoxyribonucleic acid)

Double stranded(helix), in the nucleus, + is STABLE

RNA (Ribonucleic acid)

Single stranded(helix), in cytosol and ribose, + can only use it ONCE

Vitamins

Organic substances made by plants to help enzymes + biochemical processes. Animals cannot make them (humans can make vitamin D)

Mineral

Inorganic substances that originate in soil and water to help with enzyme actions. Should be consumed in small quantities.

Enzymes

Proteins that are biological catalysts by increasing reaction rates by reducing the activation energy; end in -ase.

What enzymes are made of

Globular proteins with an active site (made of few amini acids)

Homeostatic temperature

Balanced temp. (37^oC) in human bodies

Exergonic

Release energy

Endergonic

Absorb energy

Homeostasis

A steady, balanced state

Negative feedback

Mechanism used to keep our bodies in homeostasis

Positive feedback

Helps to accelerate a reaction

Function of enzymes

Helps break down bonds or bring them together between molecules that compose the substrate

Lock & Key

Enzyme and substrate have shapes that fit like pieces (very precise)

Induced fit

Enzyme change shape slightly to accommodate the substrate

Factors to influence enzyme reactions

Temp., enzyme concentration, + pH

Coenzymes

Organic molecules that bind to an active site of the enzyme

Cofactor

“Helper” molecules (organic or inorganic) that drag the substrate to the moelcule

Allosteric site

Place on an enzyme where a molecules can bind, changing the shape and preventing the substrate to connect

Allosteric activity

Any action involving the allosteric site