4.1.3 Transport in Cells Flashcards
4.1 Cell Biology (21 cards)
How can substances move in and out of cells? Define this process.
Diffusion, which is the spreading out of the particles of any substance in solution, or particles in gas resulting in a NET movement from an area of higher concentration to an area of lower concentration (with the concentration gradient).
What are some examples of substances being in the process of substances moving in and out of cells?
Oxygen, Carbon Dioxide
What are factors that affect the rate of the process of substances moving in and out of cells?
- The difference in concentrations (concentration gradient)
- The temperature
- The surface area of the membrane
What does a single-celled organism have that allows sufficient transport of molecules into and out of the cell?
It has a relatively large surface area to volume ratio
Why do multicellular organisms need exchange surfaces and a transport system?
To meet the needs of surface area to volume ratio
Which structures are adapted for exchanging materials in mammals?
Small intestine and lungs
Which structures are adapted for exchanging materials in fish?
Gills
Which structures are adapted for exchanging materials in plants?
Roots and leaves
What is the primary purpose of specialised surfaces and organ systems in multicellular organisms?
To allow sufficient molecules to be transported into and out of cells
What are the factors that increase the effectiveness of an exchange surface?
- Large surface area
- Thin membrane for short diffusion path
- Efficient blood supply (in animals)
- Ventilation (for gaseous exchange in animals)
What is osmosis?
The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
Osmosis is essential for maintaining cell turgor and overall cell function.
What is the role of a partially permeable membrane in osmosis?
It allows water to move while restricting the passage of solutes.
This selective permeability is crucial for maintaining the appropriate concentration gradients.
What are simple compound measures of rate of water uptake?
Methods used to quantify how much water is absorbed by plant tissues over time.
This can include measurements like milliliters of water absorbed per gram of tissue.
Fill in the blank: Osmosis is the diffusion of water from a _______ solution to a ___________ solution.
dilute
concentrated
True or False: Osmosis only occurs in plant cells.
False
Osmosis occurs in all living cells, including animal cells.
What are percentiles used for in the context of osmosis?
To compare rates of water uptake among different samples or groups.
Percentiles provide a way to understand how a specific measurement ranks within a dataset.
What is active transport?
Active Transport moves substances from a low concentration to a high concentration (against concentration gradient)
True or False: Active Transport requires energy
True
What is the purpose of active transport in plants?
Active transport allows mineral ions to be absorbed into plant root hairs from very dilute solutions in the soil.
Plants require ions for healthy growth.
How does active transport function in the human gut?
Active transport allows sugar molecules to be absorbed from lower concentrations in the gut into the blood, which has a higher sugar concentration.
Sugar molecules are used for cell respiration.
Fill in the blank: Active transport allows _______ to be absorbed into plant root hairs.
mineral ions
