animal tissues, organs and systems (topic 2) Flashcards
to show the experiment was more repeatable
what did the student do with the anomalous result
- ignored it
- didnt use it
amylase is the enzyme that controls the breakdown of starch to glucose, describe how the student could investigate the effect of pH on the breakdown of starch by amylase (4)
- range of at least 3 pH values
- keep amount or concentration of starch and amylase the same
- keep temperature the same using water bath
- use iodine test to make qualitative observations
- observe colour changes at different temperatures
- do repeats at each pH
a food has a sugar substitute in it, why must it say on the packet which sugar substitute it is
idea of informed choice
where is the enzyme amylase produced in the human body
salivary glands
name three chemical substances transported by the plasma
- amino acids
- antibodies
- antitoxins
- carbon dioxide
- enzymes
- glucose
describe how pathogens cause infections and describe how the immune system defends the body against these pathogens (6)
- bacteria and viruses are pathogens
- they reproduce rapidly inside the body
- bacteria may produce toxins
- viruses live (and reproduce) inside cells (causing damage)
white blood cells help to defend against pathogens by: - ingesting pathogens
- to destroy pathogen
- producing antibodies
- to destroy specific pathogens
- producing antitoxins
- to counteract toxins
- this leads to immunity from that pathogen
describe three ways fossils can be made (3)
- parts of organisms have not decayed
- conditions needed for decay are absent
- parts of the organism are replaced by other materials as they decay
give two reasons why animals may become extinct
- new predators
- new diseases
- better competitors
- catastrophe eg volcanic eruption, meteor
- prey dies out or lack of food
fructose is used instead of sucrose in many types of food, suggest why, use information from table 1 in your answer (3)
- fructose is sweeter than sucrose
- can use less fructose (for same sweetness)
- cheaper
A and B are two enzymes that digest carbohydrates, what general name do scientists give to enzymes like A and B
carbohydrases
it is an advantage to carry out these reactions in the industrial production of HFCS at 60 °C, suggest why (2)
- faster reaction
- so more product made
- enzyme can be re-used / not wasted
- constant-flow system
- can be automated
- product not contaminated by enzyme / enzyme may give allergic reaction
(3)
- volume is smaller so costs less to heat
- temperature is cooler so costs less to heat
- reaction time is shorter so reduces running costs
- 1 stage product refining instead of 4, leading to reduced cost
1500 x 3 = 4500
glycerol
some students investigated the effect of bile on the digestion of fat by lipase
fatty acid (production)
suggest one reason why the contents of both beakers had the same pH at the
end of the investigations
- all fat / milk digested
- same amount of fatty acids present
describe how you would carry out an investigation to compare the amounts of catalase in different parts of bean seedlings, you should include details of how you would make sure your results give a valid comparison of the amounts of catalase (6)
- bean seedlings of same age
- cut material from same part of each organ
- equal mass of each organ
- grind
- in equal amounts of water
- equal volumes of hydrogen peroxide solution
- same temperature
- quantitative measure of gas production eg height of foam in mm
- for same time period
- repetitions (3+ times)
- calculate mean for each
