B3 Science

Question 1

Active site

Answer 1

the site on an enzyme where the reactants bind

Question 2

Amino acids

Answer 2

molecules made up of carbon, hydrogen, oxygen, and nitrogen that are the building blocks of proteins

Question 3

Amylase

Answer 3

enzyme that speeds up the digestion of starch into sugars

Question 4

Bile

Answer 4

neutralises stomach acid to give a high pH for the enzymes from the pancreas and small intestine to work well. It is not an enzyme

Question 5

Carbohydrases

Answer 5

enzymes that speed up the breakdown of carbohydrates into simple sugars

Question 6

Carbohydrates

Answer 6

molecules that contain only carbon, hydrogen, and oxygen. They provide the energy for the metabolism and are found in foods such as rice, potatoes, and bread

Question 7

Catalyst

Answer 7

a substance that speeds up the rate of another reaction but is not used up or changed itself

Question 8

Denatured

Answer 8

the breakdown of the molecular structure of a protein so it no longer functions

Question 9

Differentiate

Answer 9

the process where cells become specialised for a particular function

Question 10

Digestive system

Answer 10

organ system where food is digested and absorbed

Question 11

Enzymes

Answer 11

biological catalysts, usually proteins

Question 12

Fatty acids

Answer 12

part of the structure of a lipid molecule

Question 13

Glycerol

Answer 13

part of the structure of a lipid molecule

Question 14

Lipase

Answer 14

enzymes that speed up the breakdown of lipids into fatty acids and glycerol

Question 15

Lipids

Answer 15

include fats and oils and are found in foods such as butter, olive oil, and crisps. They are made of carbon, hydrogen and oxygen

Question 16

Metabolism

Answer 16

the sum of all the reactions taking place in a cell or the body of an organism

Question 17

Organ

Answer 17

an aggregation (collection ) of different tissues working together to carry out specific functions

Question 18

Protease

Answer 18

enzymes that speed up the breakdown of proteins into amino acids

Question 19

Proteins

Answer 19

molecules that contain carbon, hydrogen, oxygen, and nitrogen and are made of long chains of amino acids. They are used for building the cells and tissues of the body and to form enzymes

Question 20

Simple sugars

Answer 20

small carbohydrate units, for example glucose

Question 21

Tissues

Answer 21

a group of specialised cells with a similar structure and function

Question 22

Organelle

Answer 22

Cell structure that is specialised to carry out a particular function or job

Question 23

Cell

Answer 23

Basic structural and functional unit of a living organism

Question 24

Tissue

Answer 24

Group of cells with similar structures, working together to perform a shared function

Question 25

Organ

Answer 25

Structure made up of a group of tissues, working together to perform specific functions

Question 26

Organ system

Answer 26

Group of organs with related functions, working together to perform body functions

Question 27

Mouth

Answer 27

Working together with your teeth, the mouth grinds food and mixes it with saliva. The mouth is where digestion begins and “solid food” is changed into “chewed food”.

Question 28

Salivary Glands

Answer 28

These glands make saliva which contains an enzyme that changes some of the starches in the food to sugar

Question 29

Epiglottis

Answer 29

Flap that closes windpipe during swallowing

Question 30

Trachea (wind pipe)

Answer 30

Not part of the digestive system. Shown here with reference to the epiglottis

Question 31

Gullet

Answer 31

Also known as the gullet. It is a tough, muscular tube that pushes food from the mouth to the stomach by contractions of its walls.

Question 32

Stomach

Answer 32

Makes digestive juices called gastric juices, which break down “chewed food” into “partly digested food” before it goes to the small intestine for final digestion. Gastric juices are stored in tiny sacs (or bags) in the lining of the stomach. The stomach also serves as a storage tank for food.

Question 33

Small intestine

Answer 33

Fluids from the liver and pancreas dilute and further digest the “partly digested food”. “Digested food”, now in a liquid form, is absorbed into the bloodstream through the tiny blood vessels in the small intestine walls. The “indigestible food” goes on to the large intestine.

Question 34

Pancreas

Answer 34

Makes enzymes that break down all types of food. The pancreas sends enzymes and digestive juices into the small intestine to help reduce food to a liquid form.

Question 35

Liver

Answer 35

Produces and discharges bile, a greenish-yellow digestive fluid. Bile travels from the liver to the small intestine, where it aids in the digestion of fats. The liver stores food which it releases into the blood whenever the body needs it. Also changes some digested food into compounds needed by the body’s cells.

Question 36

Gallbladder

Answer 36

A pear-shaped pouch that lies under the liver. Extra bile is stored here in the gallbladder. Bile aids digestion by breaking up large molecules of fatty foods.

Question 37

Large intestine

Answer 37

Fluids are absorbed from “indigestible food” which becomes “solid waste”. The large intestine stores the waste material until the body is ready to get rid of it.

Question 38

Appendix

Answer 38

A small, worm-shaped organ attached to the large intestine. It does not seem to serve any purpose in the human body.

Question 39

Anus

Answer 39

End of digestive tract, where food wastes leave the body

Question 40

Ascending colon

Answer 40

the part of the large intestine that run upwards; it is located after the cecum.

Question 41

Chyme

Answer 41

food in the stomach that is partly digested and mixed with stomach acids. Chyme goes on to the small intestine for further digestion.

Question 42

Descending colon

Answer 42

the part of the large intestine that run downwards after the transverse colon and before the sigmoid colon.

Question 43

Rectum

Answer 43

the lower part of the large intestine, where feces are stored before they are excreted.

Question 44

Transverse colon

Answer 44

the part of the large intestine that runs horizontally across the abdomen.