Cell Organisation Flashcards
What is the order that specialised cells form things in?
Cells, tissues, organs, organ systems
What is a tissue?
a group of similar cells that work together to carry out a particular function
What is an example of a type of tissue?
Muscular tissue- contracts, moves what its attached to
Glandular tissue- makes and secretes chemicals (enzymes, hormones)
Epithelial tissue- covers part of the body (inside of the gut)
What is an organ?
a group of different tissues that work together to perform a certain function
What tissues is the stomach made of?
Muscular tissue- moves the stomach wall to churn food
Glandular tissue- makes digestive juices to digest food
Epithelial tissue- covers the outside and inside of stomach
What is an Organ system?
a group of organs working together to perform a specific function
What is the digestive system made up of (organs)?
- Glands (pancreas, salivary- produce digestive juices)
- stomach + small intestine, digests food
- liver, produces bile
- small intestine, absorbs soluble food molecules
- large intestine, absorbs water from undigested food, leaving faeces.
What do organ systems work together to make?
an organism
What are enzymes?
Biological catalysts that speed up useful chemical reactions in the body
Large proteins (chain of amino acids folded into unique shapes)
What is a catalyst?
a substance which increases the rate of reaction, without being changed or used up.
What is an active site?
a unique shape of an enzyme that fits onto a specific substance to catalyse its reaction
How many reactions does 1 enzyme catalyse?
1
What is the lock and key model?
- the active site of an enzyme is specific to a substrate
- the substrate binds to the enzyme, which then allows it to react and breaks off the enzyme
What factors affect enzymes?
- temperature
- pH
What do digestive enzymes break down?
Starch, proteins, lipids (big molecules)
Why do digestive enzymes break down bigger molecules (starch, proteins, lipids) ?
- they are too big to pass the walls of the digestive system
- broken down into smaller molecules like sugars (maltose, glucose), amino acids, glycerol and fatty acids
- now small can be absorbed into the bloodstream
What enzyme breaks down starch into simple sugars?
Carbohydrase (amylase)
Where is amylase produced?
- salivary glands
- pancreas
- small intestine
What enzyme breaks down protien into amino acids?
Protease
Where is protease made?
- stomach
- pancreas
- small intestine
What enzyme breaks down lipids into glycerol and fatty acids?
lipase
Where is lipase made?
- pancreas
- small intestine
What is the role of bile?
- neutralises hydrochloric acid in the stomach (enzymes in small intestine work best at lower pH/ alkaline conditions)
- emulsifies fats-> larger SA of fat, easier for lipase to digest faster
What is the role of the liver?
- Bile is produced
- emulsifies fat
- neutralises stomach acid
What is the role of the gall bladder?
- Bile is stored before being released into the small intestine
What is the role of the large intestine?
- excess water is absorbed from food
What is the role of the rectum?
- faeces is stored before being excreted through anus
What is the role of the stomach?
- pummels food with muscular walls
- produces protease enzyme, pepsin
- produces Hydrochloric acid, kills bacteria + give right pH for protease to work (pH 2)
What is the role of the pancreas?
- produces protease, amylase + lipase
- releases into small intestine
What is the role of the small intestine?
- produces protease, amylase + lipase (complete digestion)
- digestive food is absorbed out of digestive system into blood
Where are the lungs located?
the Thorax
How is the lungs separated from the lower part of the body?
with the Diaphragm
How are the lungs protected?
the Ribcage
How does air reach your lungs?
- breathed in
- through trachea
- splits into 2 tubes, Bronchi
- go into lung through Bronchioles (smaller tubes)
- reach Alveoli (small bags), gas exchange takes place
How do alveoli carry out gas exchange?
- alveoli are surrounded by a network of blood capillaries
- blood passing-> returning from body to lungs= deox, lots of CO2
- oxygen diffuses out of alveolus into blood, CO2 diffuses out of blood into alveolus (breathed out)
How is oxygen carried from the lungs to body cells?
- When blood reaches body cells, oxygen released by Red blood cells + diffuses into body cells
- CO2 diffuses out of body cells into blood, carried back to lungs