IGCSE Biology: Respiration, Exercise, and ATP

A set of 20 fill-in-the-blank practice flashcards covering cell respiration, anaerobic pathways, industrial yeast applications, cardiovascular and respiratory regulation during exercise, and ATP structure.

Respiration is a chemical reaction that takes place inside living cells to break down nutrients to release energy and produce __________.

ATP

Breathing is a muscular movement that supplies the respiratory system with oxygen during inhalation and removes waste gases such as __________ during exhalation.

carbon dioxide

The balanced chemical equation for aerobic respiration is __________.

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$$

Aerobic respiration takes place in the mitochondria, whereas anaerobic respiration takes place in the __________.

cytoplasm

Anaerobic respiration results in the incomplete breakdown of glucose, producing only __________ for each glucose molecule.

$$2\text{ ATP}$$

In muscle cells, the balanced equation for anaerobic respiration is $C_6H_{12}O_6 \rightarrow$ __________.

$$2C_3H_6O_3$$

In yeast cells, the chemical products of anaerobic respiration of glucose are carbon dioxide and __________.

ethanol

In bread making, adding water activates the __________ already present in flour to digest some of the starch to sugar.

amylases

During bread making, a protein called __________ gives the dough a sticky, elastic texture which holds the bubbles of gas.

gluten

Bread dough is baked at about $200^\circ\text{C}$, which expands gas bubbles, evaporates alcohol, and __________ the yeast.

kills

In the ethanol biofuel industry, maize is treated with amylase and __________ to produce glucose.

maltase

In respiration experiments, the release of carbon dioxide causes limewater to turn __________.

milky

Carbon dioxide release causes hydrogencarbonate indicator solution to turn from red to __________.

yellow-orange

As exercise commences, an increased concentration of carbon dioxide in the blood plasma lowers the __________ of the blood.

$$\text{pH}$$

The decrease in blood pH is detected by chemoreceptors located in the aorta and the __________.

carotid artery

The respiratory centre sends nerve impulses to the diaphragm and __________ muscles to increase the rate and depth of breathing.

intercostal

Cardiac output is calculated by multiplying stroke volume by __________.

heart rate

A mouse has a higher breathing and heart rate than an elephant because its higher surface area to volume ratio causes more heat loss by convection and __________.

radiation

Oxygen consumption during respiration can be measured using an instrument called a __________.

respirometer

An ATP molecule is composed of an organic molecule called adenosine attached to __________ phosphate groups.

three