Chapter 1- cell structure and transport Flashcards
What are chloroplasts ?
Green part of the plant, they contain chlorophyll which absorbs light for photosynthesis
What is a eukaryotic cell?
Animal and plant cells
They all have cell membrane, cytoplasm and genetic material in a nuclear
What is a prokaryote?
Bacteria- a single-celled living organism
May contain small bits of DNA
What are plasmids ?
Code for specific features such as antibiotic resistance
How are nerve cells specialised to carry signals around the body ?
1) they have lots of dendrites which make connections to other nerve cells
2) and axon to carry nerve impulses from one place to another
How are muscle cells specialised?
1) They contain special proteins that can slide over each other and make the fibres contract
2) they store glycogen to transfer energy needed for fibres to contract
What are root hair cells ?
Root hair cells are found near the tips of growing roots
They help take minerals and water up into the plant more efficiently
What do root hair cells do ?
They greatly increase the surface area so that more water can move up the cell
They have a large permanent vacuole that helps speed up the movement of water by osmosis
Mitochondria that help transport energy
What are photosynthetic cells ?
Cells that help plants make their own food by photosynthesis
How are photosynthetic cells adapted ?
They contain specialised green structures called chloroplasts that trap light
Placed in leaves so can absorb as much light as possible
Large permanent vacuole to keep the cell rigid
What are Xylem cells?
A transport tissue in plants that carry water and mineral ions from the roots to leaves and shoots higher up the plant
How are xylem cells adapted?
The xylem cells die and form long hollow tubes that allow water and mineral ions to move easily up them
Spiral rings of login make them stand tall and strong so they can hold the pressure of water
What are phloem cells ?
A specialised transport tissue that can carry food made by photosynthesis around the body
How has a phloem cell adapted ?
The cell walls between cells break down to form special sieve plates. These allow water to carry dissolved food freely up and down the tubes
What is diffusion ?
The spreading out of gas particles over a substance, they move from a high concentration to a low concentration
How is the rate of diffusion effected ?
An increase in temperature means that the particles in a gas solution move around quickly
If there is a small difference in concentration between 2 areas then diffusion will happen slowly
Where does diffusion happen?
Diffusion happens over the cell membrane
An example is oxygen from your lungs pass to your red blood cells by diffusion
What are partially permeable membranes ?
Membranes that only let some types of particles through
What is osmosis ?
Type of diffusion where only water moves across a partially permeable membrane from a dilute solution to a concentrated solution
What does isotonic mean?
When the solution outside the cell is the same as the internal concentration
What does hypertonic mean?
When the solution outside the cell is higher then the concentration inside a cell
What does hypotonic mean ?
When the solution outside the cell is lower concentration then the internal concentration
Osmosis in plants
Plants rely on osmosis to help support their stem and leaves. More water moves into plant cells by osmosis the pressure of water is known as turgid which helps the plant stay rigid
What is active transport?
Allows cells to move substances from a low concentration to a high concentration through a semi permeable membrane
