7.3 pt1

Question 1

Metabolism

Answer 1

Metabolism refers to the chemical reactions that occur inside an organism to maintain life

Question 2

Catabolic reactions

Answer 2

-Break down organic matter
-Release energy

Question 3

Anabolic reactions

Answer 3

-Build organic matter
-Store energy

Question 4

Enzymes

Answer 4

-Proteins that speed up metabolic reactions.
-Without enzymes, reactions would be to slow to maintain life
-We have around 700 enzymes in our body.
-Enzymes are not used up in a reaction.
-Enzyme activity is modelled through the lock and key method.
-Each enzyme has a specific substrate that they interact with

Question 5

homeostasis

Answer 5

-Homeostasis is a process that maintains a constant internal environment within an organism so that cells and systems can function properly despite changes to the external environment.
-Homeostasis is managed by the nervous system and the endocrine system.

Question 6

endocrine system

Answer 6

The endocrine system is made up of glands that produce hormones – chemical messengers.
-The hypothalamus receives information from thermoreceptors on the skin / inside the body
-It signals the pituitary gland that allow the thyroid stimulating hormone (TSH) to control the thyroid gland
-The thyroid gland controls the release of the hormone thyroxine into the bloodstream

Question 7

Hormones

Answer 7

-Hormones are chemical messengers produced by endocrine glands into the bloodstream.
-Hormones only affect specific target cells that have a receptor for that hormone on the cell membrane.
-Hormones are needed in small quantities and are used for:
growth,
development,
temperature control etc.

Question 8

Hypothalamus

Answer 8

The hypothalamus is a region in the brain that constantly checks our internal environment.
If a change is detected, then the hypothalamus will trigger the nervous system and endocrine system to act