Exam 1 Flashcards
What is homeostasis?
Stability (condition of being stable in the body)
If an animal’s internal body temperature is too high, how will the body respond?
Sweating
Define the term “Negative Feedback Loop”
Process that opposes changes that are outside normal range
Explain how negative feedback loops work inside the body.
- Receptors detect changes and send signal to brain
- Brain interprets signal and sends a response
- Target cell receive the signal and try to fix the problem
List 4 factors that are regulated inside the body
- Temperature
- Blood pressure
- Blood glucose levels
- Blood pH
What is a membrane?
A barrier that regulates movement of things inside and outside a cell
What is the main component of a cell membrane?
Lipid
Does diffusion require energy?
No
What is meant by the term “concentration gradient?”
Imbalance of things across the membrane
Which method of cell membrane transport requires energy?
Active Transport
Which method of transport involves easy movement across the lipid membrane?
Simple diffusion
Which method of transport involves the use of protein tunnels and DOES NOT require energy?
Facilitated diffusion
Name the important molecule that contains energy in its phosphate bonds.
ATP
What does the Sodium-Potassium Pump do?
- Moves 3 sodium outside cell
- Moves 2 potassium inside cell
Name 2 body systems that commonly use the Sodium-Potassium Pump.
- Nervous System
- Digestive System
Explain what an electrochemical gradient is.
Imbalance in electrical charge across membrane
After the Sodium-Potassium Pump does its job, what is the electrical charge inside the cell?
Negative
If the amount of sodium is higher outside the cell, where will sodium atoms want to move to by diffusion
Inside
What is osmosis?
Movement of water across a membrane
If the amount of sugar is higher outside the cell, where will water move to?
Outside
If the amount of salt is higher inside the cell, where will water move to?
Inside
Why does salt absorption from the small intestine also lead to water absorption?
Because water follows salt
What scientific name is used to describe solutions that are LOW in salt?
Hypotonic
Name the 2 types of molecules that aid in cell communication.
- Hormones
- Neurotransmitters
What body system is responsible for producing hormones?
Endocrine system
What body system is responsible for producing neurotransmitters?
Nervous system
How do peptide hormones differ from steroid hormones?
- Peptide - made of protein
- Steroid - made of lipid
Explain the mechanism of how steroid hormones affect target cells.
- The steroid hormone passes directly through cell membrane and enters cell
- Next, steroid hormone binds to an inside receptor to form a complex
- The complex acts on the nucleus to increase transcription of certain genes
- This will increase or decrease certain activity on the target cell
Explain the mechanism of how peptide hormones affect target cells.
- The peptide hormone binds to receptor on cell membrane surface
- Binding to the receptor triggers a complex signaling cascade inside cell
- during the cascade, the message is passed to different relay molecules
- The last relay molecule acts on nucleus to increase transcription
- This will increase or decrease certain activity on the target cell
Which gland of the endocrine system is nicknamed “The Master Gland”?
Pituitary gland
