Topic 1

What monosaccharide is this

Alpha- glucose

What monosaccharide is this

Beta- glucose

What monosaccharide is this

Fructose

What monosaccharide is this

Beta galactose

What monosaccharide is this

Ribose

What monosaccharide is this

Deoxyribose

What disaccharide is this

Sucrose

What disaccharide is this

Lactose

What monosaccharides is sucrose composed of?

Fructose and alpha glucose

What bond is shared between the units in a disaccharide

glycosidic bonds

What monosaccharides is lactose composed of?

Beta galactose and glucose

What monosaccharides is maltose composed of?

Glucose and glucose

What are the component of starch

Amylose and Amylopectin

What are polysaccharides with 3-10 monomers called

Oligosaccharides

What are polysaccharides with 11+ monomers known as

True polysaccharides

What types of substances are water soluble

Ionic and polar covalent

General formula of monosaccharides

(CH2O)n

Which monosaccharides and disaccharides are not reducing sugars

Sucrose

Why are mono/disaccharides not good energy storage units

-They are chemically active

-The are water soluble/ affect osmotic potential

Why are polysaccharides good energy storage units

-They form compact molecules

-They’re insoluble

-Chemically inactive

structure of Amylose

-Straight chain of a-glucose monomers

-Consists of only 1-4 glycosidic bonds

-Forms hydrogen bonds, spirals and becomes compact

Structure of Amylopectin

Mix of 1-4 and 1-6 bonds between a-glucose monomers

Structure of glycogen

More 1-6 bonds, more branched, better for animals

Reaction where water is produced as byproduct, and reverse reaction

Condensation, hydrolysis

Bonds between monosaccharides

1-4 or 1-6 glycodidic

Characteristics of fats

-From animals

-Solid at room temperature

Characteristics of lipids

-Liquid at room temp

-From plants

Saturated fatty acids are usually in what form

Solid

Unsaturated fatty acids are usually in what form

Liquid

Structure of triglycerides

A glycerol molecule bonded to the carboxyl groups of 3 fatty acid chains by ester bonds

Differences in atom composition of lipids and carbohydrates

Both have carbon hydrogen and oxygen, lipid have lower oxygen proportions

What can fatty acids vary in

-Chain length

-Being saturated/ unsaturated

What are essential lipids and their importance

The are polyunsaturated lipids, and humans can not produce them themselves

The general formula of saturated fatty acids

CnH2nO2

What common bonds are formed by condensation reactions

-Glycosidic

-Ester

-Peptide

-Phosphodiester

Structure of an amino acid

Amino group (NH3) and Carboxyl group (COOH) and R group attached to a central carbon atom

Primary structure

The sequence of amino acids in a chain

Secondary structure

The arrangement of the chain into 3D structures like a-helixes

Tertiary structure

The further folding of the secondary structure into complex shapes

Quaternary structure

How multiple polypeptide chains fit together

Bonds that influence shapes of proteins

-Hydrogen

-Ionic

-Disulfide

structure of fibrous proteins

Long parallel chains with little/no tertiary structure. They are insoluble and tough

Structure of collagen

Fibrous protein made from 3 alpha helixes arranged in a triple helix

structure of globular proteins

Spherical, with hydrophilic R groups outside and hydrophobic inside

Solubility of globular proteins in water

Insoluble (too large) they form a colloid instead

Structure of conjugated proteins

Have prosthetic groups

Main types of proteins

-Fibrous

-Globular

-Conjugated

What type of protein is haemoglobin

Globular and conjugated

Features of glycoproteins

-Retain more water (therefore more slippery e.g mucus)

-Digested less easily by proteases

How many oxygen molecules and atoms can haemoglobin carry

4 molecules, 8 atoms

Name of the changes in haemoglobin’s affinity after different numbers of molecules have binded

Cooperative binding/ confirmational changes/ The bohr effect

How does haemoglobin buffer blood pH

H+ ions from dissociated carbonic acid (CO2 + H2O) bind to it in so they don’t alter pH

Adaptations of blood in muscle tissues for faster O2 release during respiration

-When partial pressure of CO2 increases, it reduces haemoglobin’s affinity to oxygen so it dissociates faster.

-CO2 also reacts with water to form carbonic acid, which dissociates into carbonate and H+ ions. These bind to haemoglobin, reducing its affinity as well

Methods of CO2 transfer in blood

-As carbinohaemoglobin

-In blood plasma

-As Hydrogen and carbonate ions

Types of circulation in mamals

-systemic circulation

-pulmonary circulation

Benefits of double circulation

-High concentration gradient for gas exchange

-Oxygenated blood is delivered fast at high pressures

-Deoxygenated blood is at low pressures to prevent damage to lungs and vessels

Specific stages of the cardiac cycle

Atrial systole —> AV valves close —> ventricular systole —> SV valves close —> diastole

Layers of blood vessels

• Lumen

• Tunica intima (endothelial lining)

• Tunica media (Smooth muscle, elastic fibres)

• Tunica externa (tough layer of collagen)

Tissue composition of artieries

-Higher proportions of elastic fibres for blood surges and elastic recoil

-Peripheral arteries have less elastic fibre due to lower bp, and more muscle tissue to control blood flow

-All have high collagen

Adaptations of veins

-Larger lumen to carry more blood

-Thin muscle and elastic fibres due to lower bp

-Often in between muscles which push blood through when contracted

-Has valves to prevent backflow

Adaptations of capillaries

-Small lumen lets through only one RBC at a time, more diffusion

-One cell thick walls for short diffusion distance and the ability to branch between cells

Adaptations of erythrocytes

-Bioconcave for larger SA:V

-No nucleus, more space

-A lot of haemoglobin

The blood clotting cascade

Platelets have contact with exposed vessels and activate, releasing:

-Seratonin, causes vasoconstriction

-Thromboplastin

—> has contact with prothrombin in blood stream and catalyses its breakdown to thrombin

—> thrombin catalyses fibrinogen into fibrin

—> fibrin firms a mesh (clot)

Which elements of the clotting cascade are soluble

-Prothrombin

-Fibrinogen

The breakdown of prothrombin requires

Ca 2+ ions

Composition of LDLs

-Less proteins

-More saturated fats

Composition of HDLs

-More proteins

-Unsaturated fats

Role of LDLs and HDLs in atherosclerosis

-HDLs carry cholesterol and deposit it in the liver for removal

-LDLs carry cholesterol and deposit it in plaques

Benefits of antioxidants

They prevent cholesterol in atheromas from oxidising and triggering inflammation

Risks of atheromas

-Reduces elasticity —> high bp, rupturing

-Reducing lumen size —> high bp

A thrombus

A clot attached to the vessel wall

An aneurism

Blood buildup behind a blockage, weakening artery walls. It may split and cause internal bleeding

Possible test for atherosclerosis

Proteins in urine due to high bp in kidney blood

Possible consequences of atherosclerosis

• Damage to retina blood vessels —> blindness

• Interruption in blood supply to brain causing a stroke

• Blockage in coronary arteries causing angina or myocardial infarction

Symptoms of angina

gripping chest pain and breathlessness, stops when exercise is stopped

Symptoms of myocardial infarction

Random severe chest pain, death if not assisted

Diseases with multiple risk factors are

Multifactorial

Studies over a long timeline

Longitudinal studies

Research project on all the data available from a topic

Metadata analysis

Non modifiable risk factors for atherosclerosis

-Age, (vessels become less elastic)

-Gender (oestrogen reduces plaque buildup)

-Genes (e.g. less elastic arteries)

Modifiable risk factors for atherosclerosis

-Smoking (nicotine raises bp + chemicals that damage walls)

-Sedentary lifestyle

-Hypertension

-Obesity which can cause Hbp and diabetes

-Diet and balance of lipids, Vit C deficiency

Assessors of risk

• BMI

• Waist to hip ratio

Formula for BMI

Mass in Kg/ (height in m)²

Formula for waist to hip ratio

Waist size in cm/ Hip size in cm

Waist to hip ratio expected in healthy men and women

Men - <0.9

Women - <0.85

Test for Vit C

DCPIP, blue oxidising agent, turns colourless when reduced by vit C

How can Vit C conc be calculated

(Volume of standard solution added/ Volume of fruit juice added) x conc standard solution

Treatments for atherosclerosis

• Antihypertensives

  - Diuretics

  - Beta blockers

  - Sympathetic nerve inhibitors e.g. ACE inhibitors

• Statins

  - Plant stanols and sterols

• Anticoagulants

• Platelet inhibitory drugs

How do diuretics work

Reduce bp by increasing proportion of water in urine, and so decreasing blood volume

How do beta blockers work

They reduce hypertension by blocking the heart’s response to hormones like adrenaline

How do sympathetic nerve inhibitors work

Prevent signals to the arteries for vasoconstriction

How do ACE inhibitors work

They block production of a hormone which causes vasoconstriction

Possible side effects of taking antihypertensives

-Low bp (possible falling in the elderly)

-coughing, swelling, impotence, fatigue ecc.

How do statins work

They block the enzyme that makes cholesterol in the liver, blocking LDL production and inflammation

Benefits of statins as treatment

-Improve other conseguences of high cholesterol levels

-Seemingly effective in all groups of people

-Long lasting effect even after drug is stopped

-Come in plant Stanols and Sterol forms which can be included in diet

Disadvantages of taking statins

-Side effects like nausea, constipation, diarrhoea

-Low chance of fatal muscle inflammation

-Low chance of liver problems, possible failure

-Patients may be less careful in maintaining diet, causing other health problems

How do anticoagulants work

They interfere with the blood clotting cascade

Risks of taking anticoagulants

Internal bleeding could be fatal, they must be controlled very carefully

How do platelet inhibitory drugs work

Reduce clotting by making platelets stick together less

Risks of taking platelet inhibitory drugs

Stomach irritation, major stomach bleeds