Year 9 Science

1
Why do we eat?

• Year 9 Science

2
Food

• Type

• Use

• Carbohydrate
• Fat
• Protein
• Sugars

• Long term energy
• Protecting organs and long term energy store
• Making muscle, enzymes, skin, hair
• Fast energy

3
Food tests

• Food type

• Test

• Protein
• Sugar
• Fat
• Carbohydrate

• Biuret turns purple if protein is present
• Benedicts turns from blue to red/brown if sugar
  is present
• Greaseproof paper gets an oily residue
• Iodine turns blue/black if starch is present

4
Carnivore

• Only eats meat
• E.g. Spider, lion
• Its survival is dependent on finding and catching
  prey

Top predator Nothing eats him!
5
Carnivore Teeth Adaptation
6
Herbivore

• Only eats plants
• E.g. Cow, aphid
• Depends on a large supply of plant matter

7
Herbivore Teeth Adaptation
8
Omnivore

• Eats a mixture of plants and animals
• E.g. Pigs, humans
• Increased chance of survival as they are not
  restricted to one diet.

9
Decomposers

• Breaks down dead material
• E.g. Bacteria, fungi

10
Primary Producers (Plants)

• Plants can make their own food using
• Sunlight
• Chlorophyll
• Water
• Carbon dioxide
• How are all the consumers and producers linked?

11
Definitions

• Trophic level
• Producer
• Consumer

feeding group in food chain (eg Herbivore)
makes own food eats other organisms for food
12
Consumers
Shark
Top Predator
Fish
Carnivore
Zooplankton
Herbivore
Phytoplankton
Producer
Label the trophic levels as herbivore, carnivore,
producer, top predator. Indicate which are
consumers.
13
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14
Food Chains

• Food chains describe how organisms gain______
  from eating each other in a community.
• Plants are called _______ because they make
  glucose using energy from the ______
• _________ must eat other organisms for their
  _______ and nutrients.

Food
Producers
Sun
Consumers
Energy
15
Energy Pyramids
Only about 10 of energy passed on between
trophic levels
Few Carnivores
More Herbivores
Most is lost through the organisms living
processes
All supported by energy from producers
16
The Digestive System
(Breaking food down into smaller pieces)
Lets find out what happened to your breakfast
today!

• Mouth
• Oesophagus
• Stomach
• Small Intestine
• Liver
• Large Intestine
• Gall Bladder
• Pancreas
• Rectum
• Anus

17
Mouth

• Teeth
• (mechanical breakdown)
• Incisors used for cutting
• Canines used for stabbing and holding
• Molars large surface area used for grinding
• Saliva
• (chemical breakdown)
• Breaks down carbohydrate

18
Oesophagus

• Approximately 25cm long
• Moves food from the throat to the stomach
• Muscle movement called peristalsis
• If acid from the stomach gets in here thats
  heartburn.

19
Stomach

• Stores the food you eat
• Chemically breaks it down into tiny pieces
• Mixes food with digestive juices
• Acid in the stomach kills bacteria

20
Small Intestine

• Small intestines are roughly 6 metres long.
• Enzymes and bile are added.
• Villi increase the surface area to help
  absorbtion.
• Nutrients from the food pass into the bloodstream
  through the small intestine walls.

21
Liver

• Directly affects digestion by producing bile
• Bile helps dissolve fat
• Processes nutrients in the blood, filters out
  toxins and waste.
• Is often called the bodys energy factory

22
Gall Bladder

• Stores bile from the liver
• Delivers bile when food is digested
• Fatty diets can cause gallstones

23
Pancreas

• Produces compounds to digest fats and proteins
• Neutralizes acids that enter small intestine
• Regulates blood sugar by producing insulin

24
Large Intestine

• About 1.5 metres long
• Accepts what small intestines dont absorb.
• Absorbs water and minerals from the waste matter.

25
Rectum and Anus

• Rectum
• About 15cm long
• Stores waste before egestion.
• Anus
• Muscular ring that controls egestion.

26
Write the name of each colored organ

• Green
• Red
• Pink
• Brown
• Purple
• Green
• Yellow

27
Answers

• Green Oesophagus
• Red Stomach
• Pink Small Intestine
• Brown Large Intestine
• Purple Liver
• Green Gall Bladder
• Yellow Pancreas

28
Cells

• Cells are the building blocks of life

• All cells have the following in common
• Nucleus
• Cytoplasm
• Mitochondria
• Cell membrane
• Plant cells also have a cell wall and chloroplasts

29
Function of cell organelles

• Nucleus
• largest organelle
• control centre
• Instructions for the whole body
• Cell membrane
• Controls the entry and exit of material
• Cytoplasm
• Liquid containing cell parts and nutrients
• Mitochondria
• Powerhouse (burns energy from food)

30
Turning food into energy

• Respiration is the conversion of glucose into
  energy
• Glucose is burnt with oxygen
• It takes place in the Mitochondria

C6H12O6 6O2 6CO2 6H2O
ENERGY
Carbon Dioxide
Water
ENERGY
Glucose
Oxygen
31
Circulatory System
32
Anatomy of the Heart

• Oxygenated blood
• To the body
• LHS thicker
• Deoxygenated blood
• To the lungs

33
Blood Vessels
34
Structure of Arteries

• Oxygenated blood leaving heart
• High pressure
• Thick muscular walls

35
Structure of Capillaries

• Carry blood to cells
• Remove waste
• Deliver oxygen
• Deliver food
• Single file r.b.c.
• Very thin walls (single cell thick)

36
Structure of Veins

• Deoxygenated blood returning to heart
• Thin walls
• Low pressure
• Valves
• Muscle contraction

37
Blood

• Plasma
• Liquid carries other components
• Red Blood Cells
• Carry oxygen and Carbon Dioxide
• White Blood Cells
• Fight disease
• Platelets
• Clotting