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AQA GCSE Biology > Organisation > Flashcards

Flashcards in Organisation Deck (20):

What is tissue?

Tissue is a group of similar cells that work together to carry out a particular function. It can include more than one type of cell.


What are some examples of tissues in mammals?

-Muscular tissue (contracts)
-Glandular Tissue (makes and secretes chemicals)
-Epithelial Tissue (covers some part of body)


What is an organ?

A group of different tissues which work together to perform a certain function


What tissues are the organs in the stomach made of?

-Muscular Tissue moves stomach wall to churn food
-Glandular Tissue makes digestive juices to digest food
-Epithelial tissue covers outside and inside of stomach


What is an organ system?

A group of organs working together to perform a particular function


What is a common example of an organ system and how does it work?

Digestive system:
-Glands produce digestive juices
-Stomach and small intestine digest food
-Liver produces bile
-Small intestine absorbs soluble food molecules
-Large intestine absorbs water from undigested food


"Organ systems work together to make _____"

Entire Organisms


What needs to happen inside your body and cells for you to work?

Chemical reactions to get the right amount of substances


Why are enzymes useful?

They act as a biological catalyst. Catalysts also reduce the need for high temperatures and we only have enzymes to speed up useful chemical reactions in the body


Define Catalyst:

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


What are enzymes made of?

Enzymes are all large proteins and all proteins are made up of chains of amino acids. These chains are folded into unique shapes, which enzymes need to do their jobs


What do chemical reactions usually involve?

Things being split apart or joined together


What is the name of the place where the substrate fits into the enzyme?

Active site


Why do enzymes usually only catalyse one specific reaction?

Because for an enzyme to work, the substrate has to fit into its active site. If the substrate doesn't match the enzymes active site, then the reaction won't be catalysed


What is the "induced fit" model of enzyme action?

Where the active site changes shape a little as the substrate binds to it to get a tighter fit.


How does an enzyme become denatured with temperature?

Increasing the temperatures, increases the rate of a reaction at first. However, if it gets too hot, some of the bonds holding the enzyme together break. This changes the shape of the enzymes active site, so the substrate won't fit any more.


What condition, other than temperature effects the functionality of an enzyme?

Ph. If it is too high or low, the Ph interferes with the bonds holding the enzyme together. This changes the shape of the active site rendering the enzyme denatures


What is rate a measure of?

How much something changes over time


What is the formula to calculate the rate of a reaction where an experiment measures how much something changes over time?

Rate of Reaction = Change(amount of product formed) ÷ time (cm3/s)


What is the formula to calculate the rate of a reaction when time is measured?

Rate = 1000 ÷ time (s-1)