UNIT 12 Respiration Flashcards
uses of energy in living organisms,
including:
muscle contraction,
protein synthesis,
cell division,
active transport,
growth,
the passage of nerve impulses
& the maintenance of a constant body temperature
Investigate and describe the effect of temperature on respiration in yeast
y-axis = respiration in yeast
x-axis = temperature
What does respiration use?
Too low temp? Too high?
ENZYMES.
temp too low = less collisions
35 degrees Celsius - optimal temp for maximum respiration. Maximum number of collisions without denaturing
Temp too high = enzymes denature
What is yeast?
Single-celled fungus
Cell wall of chitin
Describe aerobic respiration
the chemical reactions in cells that use oxygen to break down
nutrient molecules to release energy
breakdown of glucose to release energy using oxygen
Pro & con of aerobic
Pro: releases more energy per glucose molecule (38 ATP per glucose molecule)
Con: requires oxygen
word & symbol equation for aerobic respiration
glucose + oxygen → carbon dioxide + water
C6H12O6 + 6O2 → 6CO2 + 6H2O
Describe anaerobic respiration
the chemical reactions in cells that break down nutrient
molecules to release energy without using oxygen
breakdown of glucose to release energy without oxygen
this produces less etc. than aerobic?
ANaerobic respiration releases much LESS energy per glucose molecule than aerobic
respiration
Pros, cons
Pros: does not require oxygen
Cons: produces much less energy per glucose molecule (2 ATP per glucose)
& produces lactic acid creating an oxygen debt that must be paid back later
word & symbol equation for anaerobic respiration in yeast
glucose → alcohol + carbon dioxide
C6H12O6 → 2C2H5OH + 2CO2
word equation for anaerobic respiration in muscles during vigorous exercise
IN ANIMALS
glucose → lactic acid
C6H12O6 → 2C3H6O3
lactic acid … during exercise does what?
builds up in muscles and blood during vigorous exercise causing an oxygen debt
Outline how the oxygen debt is removed after exercise
1.
- continuation of fast heart rate to transport lactic acid in the blood from the muscles to the liver
2.
- continuation of deeper and faster breathing
to supply oxygen for aerobic respiration of lactic acid [back to pyruvate]
3.
- aerobic respiration of lactic acid in the liver
Investigate & describe effect of temp on respiration in yeast -
What happens when we can’t get enough oxygen for aerobic respiration?
- When does this happen?
Vigorous exercise => bodies aerobically respire at a high rate
During period, oxygen is used faster in body cells than it can be replaced by gas exchange; breathing deeper & heart pumping hard bc body is re-paying oxygen debt since -
SO
- SO how do body cells continue producing more energy?
So if body cells run out of oxygen they can still produce more energy using anaerobic respiration
BUT much less efficient & creates lactic acid
3.
Anaerobic respiration creates an oxygen debt as oxygen is required to convert lactic acid back to pyruvic acid in the liver
Define respiration [2]
chemical REACTIONS that breakdown glucose
to release energy
inside cells
Explain why there is a steep increase in the man’s oxygen consumption at the start of the exercise [4]
📌 increase in muscle contraction
📌 increase in demand for energy, ATP
📌 increase in rate of respiration
📌 aerobic respiration
[heart beats faster]
10 mins after man had stopped rowing for O2 consumption to decrease to resting
draw line btwn 20-35 to show change in O2 consumption after exer. stopped [2]
line decreases immediately at 20 min
line reaches 0.2 dm^3 min^-1 at 30 min
Explain why the man’s oxygen consumption did not return to the resting value immediately after exercise [4]
📌 oxygen debt
📌 during exercise oxygen not supplied fast enough [from lung]
📌 to muscles
📌 anaerobic respiration occurred doing exercise
📌 lactic acid produced, builds up in muscle
Describe what oxygen debt is
lactic acid builds up in muscles & blood after vigorous exercise
this requires oxygen to be broken down
amount required = oxygen debt
Name two industrial processes that rely on anaerobic respiration of yeast.
alcohol production (for consumption);
alcohol for fuel;
bread making
The results for oxygen and carbon dioxide in the samples of breathed out air taken
before and after exercise are different.
Describe and explain these differences. [3]
after exercise less oxygen and more carbon dioxide / ora ;
use of data with % to quantify (for either oxygen or carbon dioxide) ;
more oxygen, absorbed / is needed / used up ;
more carbon dioxide, produced ;
more gas exchange ;
more respiration
Explain why the changes shown in Table 4.2 occur during exercise.
muscles contract ;
need more energy ;
increase in need for oxygen ; ORA
removal of (more) carbon dioxide ;
(increase in) aerobic respiration ;
anaerobic respiration also occurs ;
developing oxygen debt
Describe how the muscles identified in Fig. 4.1 work to move the forearm up.
biceps contracts
triceps relaxes
Describe the athlete’s oxygen consumption during and after the race as shown in
Fig. 4.2., using figures in graph
before:
- oxygen consumption increases as exercise starts
- levels off / increase slows down during the race
– using data;; Maximum is 2.4dm3 min 1
after:
- starts to decrease, immediately at the end of the race / at 18
minutes
- gradually decreases after exercise
Explain why the oxygen consumption does not return immediately to the resting level after the exercise is finished. [5]
oxygen debt
not enough oxygen supplied (to muscles) during exercise
to muscles
anaerobic respiration
lactic acid produced
lactic acid, broken down
Compare the effect of walking and marathon running on energy reserves.
reserves last longer for walking / ora ;
(approx) 4 times longer
Suggest which two energy reserves would be most readily available to muscles
during exercise.
+++ two food groups to which the energy reserves in Table 5.1 belong?
glucose and muscle glycogen
+++ fat and carbohydrate
Suggest why athletes eat foods high in
(i) proteins, during training; [1]
(ii) carbohydrates, for three days before a marathon race. [2]
i) muscle, growth / development / repair
ii) to build up, energy stores ;
converted to fat / stored as fat ;
Suggest and explain why a sprinter can use mainly anaerobic respiration during
the race, while a marathon runner needs to use aerobic respiration. [4]
short, time / distance, for sprint or long, time / distance, for marathon ;
sprint needs (lots of) energy quickly / marathon needs energy over long
period ;
sprint oxygen supply not sufficient / oxygen supplied during marathon ;
anaerobic does not need oxygen / aerobic needs oxygen ;
Explain how, during a marathon race, the blood glucose concentration stays fairly
constant, but the mass of glycogen in the liver decreases. [2]
glycogen in liver broken down to glucose ;
glucose from liver enters the blood ;
Name the organ where deamination takes place.
liver
State the type of respiration shown in Fig. 5.1.
Explain your answer.
type of respiration
explanation
aerobic ;
carbon dioxide / water / no lactic acid, produced ;
The urea produced is transported to the kidney, where it is excreted.
Describe how urea is transported in the blood to the kidney. [2]
soluble
in plasma
kidney tubule & associated blood vessels.
name of part & functions
- LOOK AT DIAGRAM
A - glomerulus ;; filtering (blood) ;
B - capsule ;; collects filtrate / allows filtration ;
C - tubule ;; (selective) reabsorption ;
D - collecting duct ;; (re)absorbs water / passes urine to pelvis ;
The volume of blood filtered by the kidneys is 1.18 dm3
min 1
.
(i) Calculate the total volume of blood filtered in 24 hours.
ii) total volume of urine produced in 24 hours is 1.7 dm3
, calculate the
percentage volume of the filtered blood excreted as urine in 24 hours.
1.18 × 60 × 24 / 1.18 × 1440
1699
——- 1.7 / 1700 × 100
0.1 (%)
