Grade achieved: 9
I have put so much hard work into making this set of notes. Achieving grade 9 and constantly getting top grades at school proved that my hard work paid off.
My notes are mostly based on 10+ years of mark schemes from past papers, and some from revision guides + online reso...
2.1 Principles of organisation ................................................. 2
2.2 Animal tissues, organs and organ systems ........................ 2
2.2.1 The human digestive system ......................................................................................2
2.2.2 The heart and blood vessels .......................................................................................5
2.2.3 Blood ...........................................................................................................................6
2.2.4 Coronary heart disease: a non-communicable disease ..............................................7
2.2.5 Health issues ...............................................................................................................9
2.2.6 The effect of lifestyle on some non-communicable diseases ...................................10
2.2.7 Cancer .......................................................................................................................10
2.3 Plant tissues, organs and systems ................................... 11
2.3.1 Plant tissues ..............................................................................................................11
2.3.2 Plant organ system ...................................................................................................12
1
, AQA GCSE Biology notes Topic 2 – Organisation
2.1 Principles of organisation
Cells → tissues → organs → organ system → organism
Cells - basic structural & functional units of living organisms
Muscular • Contracts to move things attached to it
• In stomach, contracts to move food
Glandular • Contains secretory cells
• Produce & release substances (enzymes, hormones)
Epithelial • Covers outside of body & internal organs
Tissues - a group of cells with similar structure & function working tgt
In stomach
Muscular • Contract to churn food
Glandular • Produce digestive juice to digest food with enzyme & HCl
Epithelial • Covers outside & inside of stomach
Organs - a group of different tissues working together to perform specific function
Organ system - a group of organs working together to perform specific functions
Organisms - a group of organ system working together
2.2 Animal tissues, organs and organ systems
2.2.1 The human digestive system
Balanced diet - right amount of nutrients & energy for needs
2
, AQA GCSE Biology notes Topic 2 – Organisation
What is the function of digestive system?
• An organ system in which several organs work tgt to digest & absorb food
Mouth How can mouth break down starchy foods?
• Teeth break down food
• Saliva contains amylase
Salivary • Produce saliva containing amylase
gland
Oesophagus • Muscular tube which move food to stomach
Stomach • Pummels food with muscular wall
• Produce protease, pepsin & HCl
• Gastric juice
• Water to moisten food
• HCl (pH2) to kill bacteria & help protease to work
• Pepsin to break proteins into amino acid
• Mucus to lubricate surface & protect from digestive enzyme & HCl
Bile • Made in liver & store in gall bladder
(alkaline) • Neutralise HCl from stomach to provide alkaline condition
• Emulsifies fats to break large lipid droplets into small droplets to ↑SA to ↑rate of
fat breakdown by lipase
Small • Digestion completed
intestine • Absorb digested food & nutrients to blood
• Small molecules diffuse through villi walls into blood for respiration
Adaptation
• Small intestine is very long, which gives plenty of time to complete absorption
• Villi are covered with microvilli, which increases SA to absorb quicker
• Villi contain blood capillaries, which provide rich blood supply to maintain a steep
concentration gradient to assist quick absorption
• Villi have thin walls for short diffusion pathways into blood
• Have lots of mitochondria to provide energy from respiration
Coeliac disease
• Damage villi ↓SA for absorption
• ↓ amino acid & glucose absorb
• ↓ amino acid available to build new tissues
• ↓ glucose ↓energy transfer from respiration
Large • Absorb excess water from blood
intestine • Form faeces
Rectum • Store faeces
Food chemistry
Carbohydrates
Use • Provide energy for metabolic reactions in cells in cellular respiration
Digestion • Starch → amylase → maltose + simple sugars
Made in • Salivary glands, pancreas & small intestine
Digestion sites • Mouth & small intestine
3
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper acer. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €6,77. Je zit daarna nergens aan vast.
