Spaced repetition Flashcards
How could you use this experiment (insect in test tube) to show aerobic respiration has occurred?
-hydrogencarbonate indicator in the tube with the insect would turn yellow, showing that carbon dioxide had been released by the insect]
Why is the left hand test tube included?
control experiment - to show that the colour change only occurs when the insect is present, so the organism is causing the change
Some heat energy is released during respiration. How could you show this occurred?
-Insulate the test tubes & add thermometers through the bungs, to monitor the temperature change.
-Only the tube with the insect should increase in temperature
Complete the table about amylase.
Enzyme:
Substrate:
Product:
Where Produced:
Where Acting:
Enzyme: Amylase
Substrate: Starch
Product: Maltose
Where Produced: Salivary glands, pancreas
Where Acting: Mouth, duodenum
Complete the table about pepsin.
Enzyme:
Substrate:
Product:
Where Produced:
Where Acting:
Enzyme: Pepsin
Substrate: Protein
Product: Peptide
Where Produced: Stomach wall
Where Acting: Stomach
Complete the table about trypsin/protease. Enzyme:
Substrate:
Product:
Where Produced:
Where Acting:
Enzyme: Trypsin/Protease
Substrate: Protein
Product: Amino acids
Where Produced: Pancreas
Where Acting: Duodenum
Complete the table about lipase.
Enzyme:
Substrate:
Product:
Where Produced:
Where Acting:
Enzyme: Lipase
Substrate: Lipids/Fats
Product: Fatty acids & glycerol
Where Produced: Pancreas
Where Acting: Duodenum
Complete the table about maltase.
Enzyme:
Substrate:
Product:
Where Produced:
Where Acting:
Enzyme: Maltase
Substrate: Maltose
Product: Glucose
Where Produced: Duodenum wall
Where Acting: Duodenum
Explain the functions of bile in the digestive system:
-Neutralises stomach acid, providing optimum conditions for the enzymes in the small intestine
-Emulsifies lipids, breaking large droplets into smaller droplets. This increases the surface area & allows lipase to digest the lipids more quickly and efficiently
Why is the leaf heated in ethanol? (photosynthesis starch test)
to dissolve and remove the chlorophyll from the leaf
Explain one safety precaution you should take whilst heating the leaf in ethanol (photosynthesis starch test)
-Use a water bath / no naked flames
-Because ethanol is highly flammable
Why would you seal a branch of the plant in a bag with soda lime? (photosynthesis starch test)
-to see the effect of removing carbon dioxide on photosynthesis
Why do you place the plant in a cupboard for 72 hours before setting up the experiment? (photosynthesis starch test)
-to destarch the leaf. No photosynthesis will occur, so the leaf will use the starch stores in
respiration
Describe the consequences of increasing atmospheric carbon dioxide concentrations.
-enhanced greenhouse effect;
-increased temperatures / global warming;
-ice caps melt / flooding
-droughts / loss of farmland;
-loss of habitats;
-extinction;
-spread of disease;
-extreme weather events]
Why are the three conditions needed for germination?
-Oxygen– for aerobic respiration
-Moisture – to disrupt the seed coat and allow enzymes and substrates to collide
-Warmth – to provide optimal conditions for enzymes
Explain how the rate of transpiration is affected by changes in the environment
-High humidity decreases rate – because there is a lower water vapour concentration gradient;
-High temperature increases rate – as the water molecules have more kinetic energy and evaporate more rapidly;
-High wind speeds increase rate – as the water vapour outside the leaf is blown away, increasing the concentration gradient;
-High light intensity increases rate – as the stomata open more widely;
Complete the paragraph about reflex arcs:
Reflexes don’t involve the ________
Involves sensory, _______, motor neurons
The _________ detected by a ________
An _______ impulse sent via neurons
The _________transfers message using neurotransmitters
_______ is a muscle which contracts or relaxes or a gland which secretes ______
Reflexes don’t involve the brain
Involves sensory, relay, motor neurons
Stimulus detected by a receptor
Electrical impulse sent via neurons
Synapse transfers message using neurotransmitters
Effector is a muscle which contracts or relaxes or a gland which secretes hormones
Blind spot
-area of the retina with no rods and cones; where the optic nerve leaves the eye
What happens when the eye focuses on a distant object?
-Ciliary muscles _______
-Suspensory ligaments __________
-Lens becomes _______
-_________ refraction of light
-So the image is focused on retina
-Ciliary muscles relax
-Suspensory ligaments tighten
-Lens becomes thinner
-Reduces refraction of light
-So the image is focused on retina
