Effect Of Surface Area To Volume Ratio

Question 1

What materials do organisms exchange with its environment for survival include?

Answer 1

• respiratory gases such as oxygen and co2
• heat
• nutrients such as glucose, amino acids and lipids
• excretory products such as co2 and urea

Question 2

How do organisms exchange materials with its environment for survival?

Answer 2

• cells can use diffusion to take in substances they need + get rid of waste products
• this is easier depending on organisms surface area to volume ratio

Question 3

What effect does surface area of the cell membrane have on diffusion?

Answer 3

• the larger the surface area
• the faster the diffusion rate
• as more molecules can pass thru at once

Question 4

What is the function of a cytoplasm?

Answer 4

• part of the cell where chemical reactions take place
• full of enzymes which are special chemicals as they control the chemical reactions e.g. respiration

Question 5

What effect does volume of cytoplasm in cell have on chemical reactions required to support the cell?

Answer 5

• the larger the volume of the cell
• the greater the demand for particles needed for chemical reactions that are required to support the cell

Question 6

Describe where exchange takes place and what it needs to be effective?

Answer 6

• takes place at surface of an organism
• materials absorbed are used by the cell
• cells of organism make up its volume
• S.A of an organism must be larger than volume for exchange to be effective

Question 7

How do you work out surface area?

Answer 7

• length x width = one side
• times this by amount of sides

Question 8

How do you work out volume?

Answer 8

Length x width x height

Question 9

How do you work out surface area to volume ratio?

Answer 9

Find the biggest common number both surface area number and volume number can be divided by

Question 10

What happens to SA:V as organism gets larger?

Answer 10

It decreases

Question 11

What happens to the large organisms heat as SA:V decreases?

Answer 11

• as SA:V ratio decreases as an organism gets larger
• it loses heat more slowly across its surface
• compared to a smaller organism

Question 12

How can a cell specialise to increase its SA:V ratio?

Answer 12

• can have a folded membrane (in and out squiggles like cilia)
• volume of cell stays the same
• but SA:V is larger
• which increases rate of diffusion