Organisation Flashcards
What are large multicellular organisms made up?
Are made up of organ systems
What are cells essentially?
Basic building blocks that make up all living organisms
What do specialised cells do?
They carry out a particular function
What do specialised cells form?
Tissues
What is differentiation?
Processes which cells become specialised
When does differentiation occur?
During development of a multicellular organism
What is a tissue?
A group of similar cells - work together to carry out particular function
What are tissues organised into?
Organs
What is an organ?
A group of different tissues - work together to perform certain function
What are organs organised into?
Organ systems
What is an organ system?
Organ system is a group of organs working together to perform particular job
What the purpose of the digestive system?
Breaks down and absorbs food
What are enzymes made out of?
Proteins (chains of amino acids are folded into unique shapes = enzymes can do their jobs)
What do enzymes act as?
Biological catalysts
How do enzymes work?
Every enzyme has active site (with unique shape) that fits onto substance involved in reaction (catalyse one specific reaction)
What actually happens to enzyme’s active site?
Active site changes shape a little as substrate bonds to get tighter fit (‘induced fit’ model)
Describe how enzymes work?
- Substrate attaches to active site forming ‘Enzyme Substrate Complex’
- Enzyme breaks substrate down (breaks bonds)
- Broken down substrate is released - products are produced
As you increase the temperature, what happens to rate of the reaction and why?
Increases the rate at first, enzymes have enough kinetic energy for collisions between enzymes and substrates
What happens to enzymes if you increase the temperature too high?
Some bonds holding enzyme together break = changes shape of enzyme’s active site so substrate won’t fit ∴ enzyme is denatured
What happens to enzymes if the temperature is too low?
They’re inactive - not enough kinetic energy for collisions
between enzymes and substrates
What affects enzymes (name two things)?
Temperature & pH
What happens to enzymes if the pH is too high/low?
Interferes with bonds holding enzyme together = changes shape of active site and denatures enzyme
What is often the optimum pH for enzymes?
Neutral - pH 7
Why does starch, proteins and fats are big molecules have to be broken down?
Too big to pass through walls of digestive system (insoluble) (& absorbed into bloodstream)