Biology additional Flashcards
What is the cytoplasm function
Most of the chemical reactions happen in there
It contains enzymes that control these chemical reactions
What is the nucleus function
Contains genetic material
Controls the activities of the cell
What is the function of the cell membrane
Holds the cell together
Controls what goes in and out of the cell
What is the mitochondria’s function
These are where most of the reactions for respiration takes place
Respiration releases energy that the cell needs to work on
What is the ribosomes function
These are where proteins are made in the cell
What do human/animal cells contain
Nucleus Cytoplasm Mitochondria Cell membrane Ribosomes
What does the plant cell contain
Cell wall Vacuole Chloroplasts Chlorophyll Nucleus Mitochondria Ribosomes Cytoplasm Cell membrane
What is the function of the cell wall
It is made of cellulose and it supports the cell and strengthens it
What is the function of chloroplasts
These are where photosynthesis takes place which makes food for the plant
And they also contain a green substance called chlorophyll
What is the function of the vacuole
Contains cell sap which is a weak solution of sugar and salts
What does the yeast cell have
Nucleus
Cytoplasm
Cell membrane
Cell wall
Name two single celled microorganisms
Yeast cell
Bacteria cell
What does a bacterial cell have
Cytoplasm
Cell membrane
cell wall
What is diffusion
Diffusion is the spreading out of particles from an area of high concentration to an are of low concentration
Why does diffusion happen in both solutions and gases
Because the particles in these substances are free to move about randomly
The bigger the difference in concentration……..
The bigger the difference in concentration the faster the diffusion rate
What small molecules can diffuse through cell membranes?
Oxygen
Glucose
Amino acids
Water
What cant fit through the cell membrane
Starch
Proteins
Name 4 specialized cells
Palisade leaf cells
Guard cells
Red blood cells
Sperm/egg cells
What are the three functions of palisade leaf cells
1- packed with chloroplasts for photosynthesis ( more of them are at te top of the cell so its nearer to light )
2- tall shape means a lot of surface area exposed down the side for absorbing CO2 from the air in the leaf.
3-thin shape means you can pack loads of them in a top of a leaf
What are the 5 functions of guard cells
1-kidney shape which opens and closes the stomata (pores) in a leaf
2-when plant has lots of water the guard cells fill with water and go plump and turgid (gezwollen) this makes the stomata open so gases can be exchanged for photosynthesis
3-when the plant is short of water the guard cells lose water and become flaccid making the stomata close, this helps stop too much water vapour escaping.
4-thin outer walls and thickened inner walls make opening and closing work
5-they are also sensitive to light and close at night to save water without losing out on photosynthesis
what are guard cells adapted for
They are adapted to their function of allowing gas exchange and controlling water loss within the leaf
What are the three functions of red bloodcells
1-concave (hol) shape gives big surface area for absorbing oxygen and it also helps them pass smoothly through capillaries(haarvaten) to reach body cells.
2-they are packed with haemoglobin the pigment that absorbs oxygen
3-they have no nucleus to leave even more room for haemoglobin
What are the 4 functions of sperm/egg cells
1-(egg function) to carry the female DNA and nourish the developing embryo in early stages,the egg cell contains huge food reserves to feed the embryo.
2-when a sperm fuses with the egg the egg’s membrane changes its structure to stop anymore sperm getting in, this makes sure the offspring end up with right amount of DNA.
3-(sperm function) to get the make DNA to the female DNA it has a long tail and streamlined head to help swim to the egg and there is a lot of mitochondria in the cell to give the energy needed.
4-sperm also carry enzymes in their heads to digest through the egg cell membrane.
What is the function of a specialized cell?
It carries out a particular function
What is differentiation
The process by which cells become specialized for a particular job
Order from small to big
tissues organ system cell organ organism
Cells Tissues Organ Organsystem Organism
Whats a tissue
A tissue is a group of similar cells that work together to carry out a particular function
Whats the function of a muscular tissue
It contracts to move whatever its attached to
Whats the function of a glandular tissue
It makes and secretes chemicals like enzymes and hormones
whats the function of epithelial tissue
Covers some parts of the body
Example ; inside of the gut
What is an organ
An organ is a group of different tissues that work together to perform a certain function
What tissues is the stomach made of
Muscular tissue - moves the stomach wall to churn up the food
Glandular tissue - makes the digestive juices to digest food.
Epithelial tissue - covers the outside and inside of the stomach
What is an organ system
A group of organs working together ti perform a particular function
Example; digestive system breaks down food.
What organs is the digestive system made up of
1-glands( pancreas,salivary glands) which produce digestive juices
2-stomach and small intestine which digest food.
3-liver which produces bile
4-small intestine absorbs soluble food molecules
5-large intestine which absorbs water from undigested food leaving faeces
What other molecule other than glucose that can diffuse into the cell
Oxygen
Photosynthesis equation
Carbon dioxide +water = (sunlight and chlorophyll) glucose +oxygen
What organs is the plant made of
Stems
Roots
Leaves
Function of mesophyll tissue
Where most of the photosynthesis in a plant occurs
Function Xylem and phloem
They transport water, mineral ions and sucrose around the plant
function of epidermal tissue
Covers the whole plant
Defenition of photosynthesis
It is the process that produces food in plants and algae , the food it produces is glucose
Where does photosynthesis happen
Inside chloroplasts
What do chloroplasts contain
A green substance called chlorophyll which absorbs sunlight and uses its energy to convert co2 and water into glucose
What is a by product in photosynthesis
Oxygen
What are the 4 raw materials needed for photosynthesis
1 sunlight on the leaf provides the energy for the process
2 chlorophyll contained in chloroplasts
3 water that reaches the cells via the xylem
4 co2 that diffuses into the leaf
What 3 factors could be a limiting factor for photosynthesis
- At night , LIGHT is a limiting factor
- in the winter its often the TEMPERATURE
- if its warm enough and bright enough the amount of CO2 Is limiting.
How do we control the amount of co2 ?
We dissolve different amounts of sodium hydrogencarbone in the water which gives off co2
How can temperature be a limiting factor?
When temp is too low the enzymes needed for photosynthesis work more slowly
but if the temperature gets at 45 degrees or above the enzymes needed for photosynthesis and its other reactions will be damaged
What is the most common way to artificially create the ideal environment for plants to grow?
In a greenhouse
Whats the 4 function of greenhouses
- They help to trap the suns heat
- Make sure temperature doesn’t become limiting
- In the winter heaters are used to keep temperature at the ideal level.
- In summer it could get too hot so they might use shades and ventilation to cool things down.
Why is artificial light used in greenhouses
light is always needed for photosynthesis so when the sun goes down it gives the plants more photosynthesis time.
How can carbon dioxide get increased in a greenhouse?
By using a paraffin heater, to heat the greenhouse, as the paraffin burns it makes co2 as a by-product
How do farmers keep the plants healthy and free from pests/diseases?
They keep them enclosed in a greenhouse and the farmer can add fertilizers to the soil to provide all the minerals needed for a healthy grow
What are the 5 ways that plants use glucose ?
- For respiration
- making cell walls
- making proteins
- stored in seeds
- stored as starch
How do plants use glucose in respiration
- They keep glucose in their leaves
- Then use some glucose for respiration
- This releases energy which allows them to convert the rest of glucose into other substances which they can use to build new cells and grow.
- to produce these substances they also need to to get a few minerals from soil
How do plants use glucose to make cell walls
glucose is converted into cellulose for making strong cell walls
How do plants use glucose for making proteins
Glucose is combined with nitrate ions to make amino acids which are then made into proteins
How do plants use glucose to store seeds
Glucose is turned into lipids for storing seeds.
How do plants use glucose to store starch
- glucose is stored into starch and stored in roots,stems,leaves ready for use when photosynthesis isnt happening
- starch is insoluble which makes it better for storing and a cell with lots of glucose would draw in loads of water and swell up.
- potatoe and parnsip plants store a lot of starch underground over the winter so new plants can grow from them the following spring
What is a habitat
The place where an organism lives
What is the distribution of an organism
Where an organism is found
What are the 5 environmental factors?
- Temperature
- Availability of water
- Availability of co2 and oxygen
- Availability of nutrients
- Amount of light
Where an organism is found is affected by environmental factors
Blabla
Why would an organism be more common in one area?
because there are differences in environmental factors between two areas
What are the two ways of studying the distribution of an organism?
- Measure how common an organism is in two sample areas (using quadrats) and compare them
- study how distribution changes across an area by placing quadrats along a transect
What are the 6 steps to compare how common an organism is in two sample areas?
- Place 1m^2 quadrat on the ground at random point within the first sample area
- count all the organisms within the quadrat
- repeat steps 1 and 2 as many times.
- Work out mean number of organisms per quadrat within sample area
- Repeat steps 1-4 in the second sample area
- Compare the two means
What is the mean in quadrats
Total number of organisms devided by number of quadrats
What is the mode in quadrats
Most common value
What is the median in quadrats?
It is the middle value when they are in order of size
What are the two steps to work out population size
- work out the mean number of organism per m2
2. then multiply the mean by the total area (in m2) of the habitat
What are transects used for
To help find out how organisms are distributed across an area
What are the tree things you do when an organism becomes more or less as you move from a hedge towards the middle of the field?
- Mark out a line in the area you want to study using a tape measure
- Then collect data along the line
- U can do this by just counting all the organisms you are interested in that touch the line
- Or u can collect data by using quadrats and these can be placed next to Eachother along the line or at intervals. (for example every 2 m)
When collecting environmental data you need to think about two twings ;
- Reliability
2. Validity
What do you need to do to make your results more reliable when collecting environmental data?
- take a large sample size
- use random samples because results from one spot and everywhere else is different the results wont be reproducible.
How can you keep something valid
You need to control all variables
What are catalysts
A catalyst is a substance which increases the speed of a reaction, without being changed or used up in the reaction
What are enzymes
Enzymes are catalysts produced by living things.
What would happen if you rise the temp in a reaction
This would speed up the useful and unwanted reactions and there is a limit to how far you can rise the temp inside a living creature before its a start to get damaged
What do enzymes do
Enzymes reduce the need for high temperatures and we only have enzymes to speed up the useful chemical reactions in the body.
What are enzymes made of
Enzymes are all proteins and all proteins are made up of chains of amino acids
Why do ezymes have special shapes?
- chemical reactions usually involve things being split apart or joined together
- every enzymes has special shape that fits onto substances in reaction
- ezymes usually only catalyse one reaction
- for enzyme to work has to fit its special shape and if the substance doesnt match the enzymes shape then the reaction wont be catalysed
What happens when it gets too hot for enzymes
Some of the bonds holding the enzyme together break this destroys the enzymes shape and so it wont work anymore ( it denatures)
What temp do enzymes in the body work best?
37 degrees
What other than temperature effects enzymes
If the ph is too high or low because the ph interferes with the bonds holding the enzyme together
Name 3 big molecules that are too big to pass through the walls of the digestive system
Starch , protein, fats
What optimum ph do enzymes work best at?
Its often neutral ph 7
Pepsin is enzyme that breaks down proteins in the stomach and it works best at ph 2 , it is well suited to the acidic conditions there
Name 4 smaller molecules that can pass easily through the walls of the digestive system
Sugars, amino acids, glycerol and fatty acids
What is the function of the digestive enzymes
They break down the big molecules into smaller ones