Science - Milestone 1

Question 1

What is aerobic respiration

Answer 1

The breakdown of glucose in the presence of oxygen to produce energy in the form of ATP

Question 2

What is anaerobic respiration

Answer 2

In the absence of oxygen, the incomplete breakdown of glucose produces lactic acid and a small amount of energy. Lactic acid is the waste product

Question 3

Cell membrane

Answer 3

A cell structure that controls which substances can enter or leave the cell; semipermeable.

Question 4

Cell nucleus

Answer 4

an organelle in a cell that holds the cells DNA

Question 5

Cell wall

Answer 5

A rigid structure that surrounds the cell membrane and provides support to the cell; fully permeable

Question 6

Chlorophyll

Answer 6

Green pigment in plants that absorbs light energy used to carry out photosynthesis

Question 7

Chloroplast

Answer 7

An organelle found in plant cells where photosynthesis occurs

Question 8

Concentration

Answer 8

A measurement of how much solute exists within a certain volume of solvent

Question 9

Concentration gradient

Answer 9

difference in the concentration of a substance from one location to another e.g. inside vs outside a cell

Question 10

Cytoplasm

Answer 10

A jellylike fluid inside the cell in which the organelles are suspended

Question 11

Denature

Answer 11

A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).

Question 12

Diffusion

Answer 12

The movement of particles from an area of high concentration to an area of low concentration until evenly spread

Question 13

Enzymes

Answer 13

Biological catalysts or proteins that speed up metabolic reactions (reactions in our bodies) without being used up

Question 14

Flaccid

Answer 14

Soft, drooping or inelastic. In plant cells this occurs in isotonic solutions even though solute concentrations are equal, due to loss of turgor pressure.

Question 15

Guard cells

Answer 15

Controls the opening and closing of stomata and gas exchange

Question 16

Lactic acid

Answer 16

formed in you body during anaerobic respiration; causes muscle burn

Question 17

Lock and key model

Answer 17

A key fits a specific lock like an enzyme fits specific substrates. Enzymes catalyze the reaction of specific substrates.

Question 18

Metabolism

Answer 18

the chemical processes that occur within a living organism in order to maintain life.

Question 19

Mitochondria

Answer 19

An organelle found in large numbers in most cells, in which the process of respiration and energy production occur.

Question 20

Organelle

Answer 20

A tiny cell structure that carries out a specific function within the cell

Question 21

Osmosis

Answer 21

The movement of water particles from an area of high water concentration to an area of low water concentration through a semi permeable membrane

Question 22

Palisade mesophyll

Answer 22

Layer of tall, column-shaped mesophyll cells just under the upper epidermis of a leaf, they do most of the photosynthesis

Question 23

Photosynthesis

Answer 23

The process by which plants make glucose from carbon dioxide and water in the presence of sunlight

Question 24

Respiration

Answer 24

The process by which cells break down simple food molecules to release the ENERGY they contain.

Question 25

Spongy mesophyll

Answer 25

loosely packed, irregularly shaped cells with spaces around them located below the palisade mesophyll

Question 26

Stomata

Answer 26

Small openings in the underside of a leaf which allow oxygen and carbon dioxide to diffuse through (and water vapour to exit).

Question 27

Substrate

Answer 27

The reactant on which an enzyme works.

Question 28

Turgid

Answer 28

when a cell has gained lots of fluid and is very firm

Question 29

Vacuole

Answer 29

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Question 30

Waxy cuticle

Answer 30

Forms a waterproof layer to stop water loss due to photosynthesis

Question 31

Plasmolysis

Answer 31

Water leaves the cell and the membrane has shrunk away from the cell wall. The plant wilts. (occurs in hypertonic solution)

Question 32

Isotonic

Answer 32

Having the same solute concentration as another solution.

Question 33

Hypertonic solution

Answer 33

Having a higher concentration of solute than another solution.

Question 34

Hypotonic solution

Answer 34

Solute concentration is less than that inside the cell; cell gains water

Question 35

What organelles do plant cells have

Answer 35

Cell wall Cell membrane Cytoplasm Nucleus Large vacuole Chloroplast Mitochondria

Question 36

What organelles do animal cells have

Answer 36

Cell membrane Nucleus Mitochondria Cytoplasm

Question 37

Semi-permeable

Answer 37

allows some substances to flow in and out eg. oxygen, carbon dioxide

Question 38

Anaerobic respiration takes place in the _______, producing ______ _____ which builds up in the ________ and then __________, before being broken down once ________ becomes available (______ debt is repaid).

Answer 38

cytoplasm, Lactic acid, muscles, bloodstream, oxygen, (oxygen)

Question 39

Word equation for anaerobic respiration

Answer 39

Glucose -------> lactic acid + energy (ATP)

Question 40

Which type of respiration releases more energy

Answer 40

Aerobic respiration releases more energy

Question 41

Where does aerobic and anaerobic respiration take place

Answer 41

Aerobic respiration takes place in the mitochondria and anaerobic respiration takes place in the cytoplasm

Question 42

Why does respiration require enzymes

Answer 42

Respiration requires oxygen and glucose to produce energy, and enzymes like amylase break down starch into glucose to support this process

Question 43

What is aerobic respiration word equation

Answer 43

Glucose + oxygen -------> carbon dioxide + water + energy (ATP)

Question 44

Why is enzyme reaction important to cellular functions

Answer 44

Enzymes lower activation energy, allowing reactions in photosynthesis and respiration to occur efficiently in plants and animals.

Question 45

how does a cell become turgid

Answer 45

If water moves into a plant cell the vacuole of the cell fills up, making the cell firmer. The cell is said to be TURGID.

Question 46

How does a cell become flaccid

Answer 46

If the water moves out the vacuole is less full, and shrinks, making the cell less rigid. The cell becomes FLACCID. This is when a plant loses support at wilts

Question 47

How does a cell become plasmolysed

Answer 47

If too much water leaves the cell the cell membrane pulls away from the inside of the cell wall. The cell becomes PLASMOLYSED.

Question 48

how do substances move in and out of cells

Answer 48

Substances like oxygen and carbon dioxide move in and out of cells by diffusion through the cell membrane from high to low concentration until evenly distributed.

Question 49

Effect of changes in pH on enzyme activity

Answer 49

Enzyme activity increases from pH 3 to 8, reaching its optimum at pH 8, but decreases beyond this as the enzyme begins to unravel and become denatured.

Question 50

Effect on changes in temperature on enzyme activity

Answer 50

Enzyme activity increases with temperature due to higher kinetic energy and more successful collisions, but beyond the optimum temperature, the enzyme begins to unravel and denature, causing the active site to change shape and reducing activity as the substrate no longer fits.

Question 51

Dilute

Answer 51

little amount of solute dissolved in water

Question 52

Concentrated

Answer 52

lots of solute dissolved in water

Question 53

Concentrated sugar solution

Answer 53

which a large amount of sugar (solute) is dissolved in a given amount of water (solvent