Science - Body Coordination: 7.3 Flashcards
Metabolism
Chemical reactions that occur within an organism to maintain life
Types of Reactions
- Catabolic Reaction (break down & release energy)
- Anabolic Reaction (build up & store energy)
Cellular Respiration
Glucose + Oxygen > Carbon Dioxide + Water + Energy
Enzymes
- Speed up reactions
- Lock and key
- Not used up
- Are proteins, made in ribosomes
- Reactions would be too slow to maintain life without them
- Each enzyme reacts with a specific substrate
- Around 700 in body
Homeostasis
Maintains a constant internal environment despite changes in external environment and managed by:
- Nervous System
- Endocrine System
Hormones
Chemical messengers secrete by endocrine glands into bloodstream–needs target cell with receptor
- Needed in small quantities, used for:
- Growth
- Development
- Temperature Control
Hypothalamus
- Region of the brain that constantly checks our internal environment
- Triggers nervous system/endocrine system to act when change is detected
What happens when there is too much blood sugar?
High Blood Sugar > Pancreas > Insulin > Liver changes Glucose to Glycogen (less sugar) > Insulin binds other cell receptors, glucose uptake
What happens when there is not enough blood sugar?
Low Blood Sugar > Pancreas > Glucagon > Liver changes Glycogen to Glucose (more sugar) > Less insulin for other cell receptors, less glucose uptake
Glycogen
Stored form of glucose (sugar)–stored in liver
Glucagon
Hormone that triggers liver glycogen to convert back into glucose/ enter bloodstream to be used for energy
Glucose
Sugar–a broken down version of glycogen
Endothermic
Warm-blooded creatures that:
- Generate heat through metabolic reactions
- Require thermoregulation to function properly (~37C)
What happens when the body has a low temperature?
Endocrine System:
Low Temp > Hypothalamus > Pituitary Gland sends more TSH to thyroid > thyroid sends more thyroxine to body > increased cellular respiration
Nervous System:
Vasoconstriction (nerve impulses trigger blood vessel constriction), Shivering, Piloerection/Goosebumps (contraction of muscles)
What happens when the body has a high temperature?
Endocrine System:
High Temp > Hypothalamus > Pituitary Gland sends less THS to thyroid > thyroid sends less thyroxine to body > decreased cellular respiration
Nervous System:
Vasodilation (nerve impulses trigger blood vessel dilation), sweating
