B1 - Cell structure and transport 1️⃣✅ Flashcards
What is the equation to calculate the magnification of an image? I AM
magnification = image size / actual size
What does the word magnify mean?
Magnify means making an object bigger so its easier to see
What does the word resolution mean?
Resolution is the degree in clarity of the object you are looking at, If a microscope has a high resolution, you would be able to see the specimen very clearly and in high detail
What are 2 types of eukaryotic cells?
Animal and Plant cells
What type of cell are bacteria?
Prokaryotic
Where is DNA found in plant and animal cells?
The nucleus
What is the function of the cell membrane?
To control the movement of substances in and out of the cell
What is the function of the mitochondria?
Site of respiration to transfer energy for the cell (Releases energy during respiration
What is the function of the chloroplasts?
To absorb light required for photosynthesis
What is the function of ribosomes?
To produce proteins (protein synthesis)
What is the function of the cell wall?
To strengthen and support the cell
What is the structure of the main genetic information in a prokaryotic cell?
Single loop of DNA
How are electron microscopes different to light microscopes?
Electron microscopes use beams of electrons instead of light, they cannot be used to view living samples, they are much more expensive, and have a much higher magnification and resolution
What is the function of the red blood cell?
To carry/ deliver oxygen around the body
Give three adaptations of the red blood cell
no, nucleus, contains a red pigment called haemoglobin, and has a bi-concave (curves inwards on both sides) shape
What is the function of a palisade cell?
To carry out photosynthesis in a leaf
Give two adaptations of a palisade cell?
lots of chloroplasts ,located at the top surface of the leaf to maximise light intake
What is the equation for the total magnification
total magnification = objective lens magnification x eyepiece lens magnification
1 kilometre km = ?meters
100 meters m
1m = ?cm
100 centimetres cm
1cm = ? mm
10 millimetres mm
1mm = ? μm
1000 micrometres μm
What is the function of the nucleus?
Stores genetic information and controls the activities of the cell
What is the function of the cytoplasm?
Liquid gel where chemical reactions take place
In what cell is the permanent vacuole present?
Plant cell
What is the permanent vacuole?
A cell organelle that contains cell sap
What is diffusion?
Diffusion is the net movement of particles for an area of high concentration to an area of low concentration down the concentration gradient until equilibrium is reached
Name three factors that affect the rate of diffusion
The concentration gradient (the steeper the gradient, the faster the rate of diffusion) , the temperature (higher temp = higher rate of diffusion) and the surface area of the membrane ( larger SA = higher rate)
How are the lungs adapted for efficient gas exchange?
alveoli - large surface area
one cell thick membranes - short diffusion pathway
good blood supply - maintains a steep concentration gradient and therefore the faster the molecules will diffuse
What is osmosis?
The diffusion of water molocules form a dilute solution (high concentration) to a concentrated solution (low concentration) across a partially permeable membrane until equilibrium is reached
What does equilibrium mean?
When all things are equal e.g. no difference in concentration
Give one example of osmosis in a plant.
When water moves from the soil into the root hair cell.
What is active transport?
The movement of particles against a concentration gradient, from a dilute solution to a more concentrated solution using energy from respiration
What is the movement of particles during diffusion?
Particles move down the concentration gradient from an area of high concentration to an area of low concentration
What is the movement of particles during active transport?
Particles move against the concentration gradient from an area of low concentration to an area of high concentration
Out of diffusion, osmosis and active transport what ones are passive/ active and why?
Diffusion & Osmosis - passive because they go down the concentration gradient
Active transport - active because it goes against the concentration gradient and has to use energy to do so ( it uses energy from respiration)
What is a partially permeable membrane?
A partially permeable membrane is just a membrane with very small holes in/ that only allows small molocules like oxygen, urea, water, mineral ions & glucose through
What are the adaptations of a sperm cell?
- Streamlined shape and tail for swimming
- Lots of mitochondira to maximise energy release from respiration to swim fast
What are the adaptations of a root hair cell?
- Lots of mitochondira to release energy for the active transport of mineral ions from the soil
- Large surface area to speed up absorbtion of mineral ions from soil
What does a root hair cell do?
Absorb mineral ions and water from the soil
What are the examples of when diffusion takes place?
- Humans - urea diffuses from cells into the blood for excretion, oxgygen diffuses from the air in alveloli to the bloodstream & diffusion of nutrients in small intestine into capilaries through the villi
- Plants - C02 for photosynthesis diffuses into leaves through stomata, 02 diffuses out
- Fish - gas exchange with oxgygen diffusing into the blood from gill fillaments
What are the examples of where osmosis takes place?
- Plants - water moves by osmosis from dilute solution in soil to concentrated solution in root hair cell
What are examples of where active transport takes place?
Humans - sugar concentration in small intestine absorbed into the blood when higher
Plants - Used to absorb mineral ions into root hair cells from more dilute solutions in soil
What do the villi do?
Absorb nutrients in the small intestine
What adaptations do the villi have?
- Good network of capilaries for constant blood supply
- one cell thick
- large surface area
In terms of diffusion, why is it good to have a network of capilaries and therefore a constant, strong blood supply?
Because the more constant the blood supply, the steeper the concentration gradient and therefore the quicker molocules will diffuse (maximises diffusion rates)
Label this plant cell
Label this animal cell
Label this microscope
What cells have a cell wall?
A plant cell and a bacterial cell, not an animal cell
What cells have plasmids?
Only bacterial cells
What cells have a cell membrane?
Animal, Plant & Bacterial cells
What does the cell membrane do?
Controlls the movement of substances in and out of the cell
What does the cell wall do?
Made of cellulose, it strengthens the cell
What does hypotonic mean?
When an external solution has a lower solute concentration and a higher water concentration compared to the cytoplasm of the cell
What does hypertonic mean?
When an external solution has a higher solute concentration and a lower water concentration compared to the cell cytoplasm
What does isotonic mean?
When an external solution has the same solute concentration and the same water concentration compared to the cell cytoplasm (equilibrium) therefore no difference in concentration so no gradient and no osmosis
What is a turgid cell?
A cell that has gotten bigger/ water moved inside
What is a flaccid cell?
A cell that has shrivelled up and gotten smaller as water has moved out
What happens to the rate of osmosis when temp increase?
Rate of osmosis will increase as water molecules will have more kinetic energy
What will happen to the rate of osmosis of the temperature is too high?
The selectively permeable cell membrane would be destroyed - if destroyed no difference in concentration as no membrane
