B1- cell structure and transport
B1.1 The world of the microscope
1) 1000 micrometres
2) 1000 nanometres
3) They use a beam of lights to form an image of an object
4) Up to 2000 times
5) Relatively cheap, can be used almost everywhere, can magnify live
specimens
6) 1930s
7) They use a beam of electrons to form an image
8) 2,000,000
9) Give 2D images with very high magnification and resolution.
10) Very large, very expensive, have to be kept in special temperature,
pressure, and humidity-controlled rooms.
11) Magnification of eyepiece lens x magnification of the objective
lens
12) Size of image/ size of real object
13) Size of image/ magnification
14) The ability to distinguish between two separate points
15) Resolving power
16) 200nm
B1.2 Animal and plant cells
1) The nucleus, the cytoplasm, the cell membrane, the mitochondria, the
ribosomes.
2) It controls all the activities of the cell and is surrounded by the nuclear
membrane. It contains the genes on the chromosomes that carry the
instructions for making the proteins needed to build new cells.
3) The cytoplasm is a liquid gel in which the organelles are suspended in
and where most of the chemical reactions needed for life take place
4) The cell membrane controls the passage of substances such as glucose
and mineral ions into the cell.
5) The mitochondria are the structure in the cytoplasm where aerobic
respiration takes place , releasing energy for the cell.
,6) The ribosomes are where protein synthesis takes place, making all the
proteins needed in the cell.
7) Made of cellulose, the cell wall strengthens the cell and gives it support
8) Structures found in all green parts of a plant; they are green because
they have chlorophyll inside them
9) A space in the cytoplasm filled with cell sap. It’s important for keeping
the cells rigid to support the plant.
B1.3 Eukaryotic and prokaryotic cells
1) Animal and plant cells
2) They have a cell membrane, cytoplasm, and genetic material that is
within a nucleus
3) A chemical called DNA
4) Bacteria
5) Prokaryotes
6) Smaller
7) Not enclosed in a nucleus
8) Extra small rings of DNA, they code for very specific features such as
antibiotic resistance
9) A long protein strand that lashes about
10) 10
11) 2
B1.4 specialisation in animal cells
1) To form specialised cells
2) Some do, others are adapted to work as part of a tissue, an organ, or a
whole organism.
3) To carry electrical impulses around the body of an animal
4) They have lots of dendrites to make connections to other nerve cells,
they have an axon that carries nerve impulses from one place to
another, the nerve endings or synapses are adapted to pass the impulses
to another cell. They have a lot of mitochondria to provide the energy
needed to make transmitter chemicals.
, 5) Striped
6) They contain special proteins that slide over each other making the
fibres contract, they contain many mitochondria to transfer the energy
needed for the chemical reactions that take place as the cells contract
and relax, they can store glycogen, a chemical that can be broken down
and used in cellular respiration by the mitochondria to transfer the
energy needed for the fibres to contract
7) A long tail that helps move the sperm through water or the female
reproductive system. The middle section is full of mitochondria, which
transfer the energy needed for the tail to work. There is a large nucleus
which contains the genetic information which needs to be passed on.
B1.5 specialisation in plant cells
1) The root hair cells help the plant take up water and mineral ions more
efficiently
2) Speeds up the movement of water by osmosis from the soil across the
root hair cell
3) So that they can absorb as much light as possible
4) Xylem is the transport tissue in plants that carries water and mineral
ions from the roots to the highest leaves and shoots.
5) Lignin
6) The cell dies and forms long hollow tubes that allow water and mineral
ions to move easily through them, from one end of the plant to the
other.
7) The specialised transport tissue that carries the food made by
photosynthesis around the body of the plant.
8) No
9) They break down to form special sieve plates. These allow water
carrying dissolved food to move freely up and down the tubes to where
it is needed.
, B1.6 Diffusion
1) Diffusion
2) The spreading out of the particles of a gas, or of any substance in
solution ( a solute).
3) From an area of a higher concentration to an area of lower
concentration of the particle.
4) A significant difference in concentration between two areas
5) Particles moving in – particles moving out
6) Rate of diffusion
7) A concentration gradient
8) An increase in temperature means that the particles in a gas or a
solution move around more quickly. When this happens, diffusion takes
place more rapidly as the random movement of the particles speeds up.
9) The cell membrane
10) Dissolved substances, e.g., simple sugars, glucose, oxygen, carbon
dioxide, and waste products such as urea.
11) Red blood cells
12) it moves out of the body cells into the red blood cells and then
into the air in the lungs by diffusion down a concentration gradient in a
similar way.
13) Gas exchange
14) To increase the surface area of the cell membrane.
15) Difference in concentrations, the temperature, and the available
surface area
B1.7 Osmosis
1) Membranes that only let some types of particles through
2) A solution which contains a high concentration of water, and a low
concentration of sugar.
3) A concentrated sugar solution contains a low concentration of water and
a high concentration of sugar.
4) It is a concentrated solution of sugars and salts
5) A special type of diffusion, where only water moves across a partially
permeable membrane from a dilute solution to a concentrated solution.
6) If the concentration go solutes in the solution outside the cell is the
same as the internal concentration