Cell organisation and Enzymes?

Question 1

what are Large multicellular organisms?

Answer 1

• they have different systems inside them for exchanging and transporting materials
• specialised cells form tissues which form organs, which form organ systems

Question 2

what is a tissue and a epithelial tissue?

Answer 2

• a group of similar cells that work together to carry out a function
• a type of tissue made of epithelial cells, it covers some parts of the human body (e.g inside of the gut)

Question 3

what is an organ?

Answer 3

• a group of different tissues that work together to perform a certain function
• the stomach is an organ and epithelial tissue lines the inside and outside of it

Question 4

what do organs make up organ systems?

Answer 4

• organ system is a group of organs working together to perform a function
• the digestive system is an organ system found in humans and other mammals, it breaks down and absorbs food

Question 5

what organs make up the Digestive system and what do they do?

Answer 5

• salivary glands produce digestive juices
• stomach digests food and is lined with epithelial tissue
  which is formed from epithelial cell
• liver produces bile
• large intestine absorbs water from undigested food, leaving poo
• small intestine digests food and absorbs soluble food molecules, glucose
• pancreas produces digestive juices

Question 6

what are Enzymes?

Answer 6

• controlled reactions from living things that go on inside their cells
• they are large proteins and they speed up reactions inside living things by acting as catalysts

Question 7

what is a Catalyst?

Answer 7

a substance that increases the speed of a reaction without being changed or used up in the reaction

Question 8

why do Enzymes have special shapes?

Answer 8

• every enzyme has an active site with an unique shape
• the substance involved in the reaction has to fit into the active site for the enzyme to work
• they usually only catalyse one specific reaction

Question 9

what is the lock and key model of an enzyme action?

Answer 9

• the active site of an enzyme is structured to fit a specifically shaped substrate
• when the substrate binds to the active site, the enzyme will facilitate the reaction and release products of the reaction

Question 10

how does temperature affect the rate of a reaction involving an enzyme?

Answer 10

• a higher temperature increases the rate at first but if it gets too hot, some of the bonds holding the enzyme together will break
• this changes the shape of the its active site so the substrate won’t fit anymore

Question 11

how does pH affect the rate of a reaction involving an enzyme?

Answer 11

• if the pH is too high or too low it affects the bonds holding it together
• this changed the shape of the active site and denatures the enzyme