Cell Structure Flashcards
What’s a eukaryotic cell
Cells that contain a nucleus
What’s a eukaryote
An organism that is made of of eukaryotic cells eg an elephant
What’s are prokaryotic cells
Single called organisms that do not contain a nucleus
What’s a prokaryote
Prokaryotic organisms (bacteria)
What’s dna
The genetic information found in all living organisms
What’s a ribosome
A small cell organelle in the cytoplasm where proteins are made
What’s reparation
The release of energy from glucose
What’s multicellular
Organisms made of of more than one type of cell
What type of cells are animals and plants made of
Eukaryotic cells
What type of cells are bacteria
Prokaryotic
What are prokaryotic cells like
Single celled
No nucleus
Smaller than eukaryotic cells
Have small rings of Dna (plasmid)
What size do individual bacterial cells range from
1μm - 10μm
How many μm (micrometres) make a metre
1 million
How many μm make a millimetre
1 thousand
What evolved first and why, prokaryotes or eukaryotes
Prokaryotes as they are missing some parts eukaryotes have
When is it believed prokaryotes first appeared
3.5 billion years ago
What’s the cytoplasm
The fluid part of cell inside membrane
Mainly Water
Holds components such as ribosomes
Most chemical reactions take place here
What’s the cell wall(in bacteria)
It’s provides supports, unlike plants - it’s not made of cellulose. It’s found on outside of cell membrane
What’s the single DNA loop on bacteria
Dna not arranged in complex chromosomes or held in nucleus
What’s the plasmid in bacteria
Small circular sections of Dna, that provide genetic variation for bacteria
What’s the cell membrane in bacteria
Controls substances going in and out of cell, internal extensions that have enzymes attached to them so respiration can occur in enzymes
What’s a ribosome in bacteria
Proteins made by ribosomes - found in cytoplasm
What’s diffusion
The net movement of particles from an area of high concentration to a lower concentration
What’s an organelle
A part of a cell with a specific function
What’s a chromosome
A structure containing dna
What are mitochondrian
A small cell organelle in which respiration occurs - found in cytoplasm of eukaryotic cells
What’s photosynthesis
A chemical reaction that occurs in chloroplasts of plants and algae, and stores energy in glucose
Light energy from sun converts carbon dioxide and water into glucose and oxygen and so is an energy source
What’s turgid
Describes swollen cells
Can plant and animal cells be multicellular or unicellular
Both lol
The cytoplasm is found in …
Bacteria cells
Animal cells
What does the cell membrane do
Controls substances being moved by diffusion, many cells need glucose or oxygen for respiration
What do mitochondria do?
Have stored energy in glucose which is released for 7 processes of life - without mitochondria there would be no energy and cell would die
They have many folds in them so they have a large surface area to increase rate of ernergy release
What’s do ribosomes do
Ribosomes are the site of protein synthesis in cytoplasm
How are animal cells different to bacterial cells
Animal cells unlike bacteria have processes in the nucleus, the nucleus controls activities of cell in animals
What’s parts to animal cells have in common with plant cells
A nucleus
Mitochondria
Ribosomes
What are the organelles that plants only have
Chloroplasts
Cell wall
Vacuole
What are chloroplast
They are full of chlorophyll to absorb light for photosynthesis
What’s the cell wall in plants
Made of cellulose
Provides structure to catch light energy
What’s the vacuole
It’s a storage area filled with sap to keep cell turgid
What are plants often green
They contain green chlorophyll
What’s biconcave
It. Describes a shape that dip curves inwards on both sides
What are ova (ovum singular)
Eggs
What’s an axon
The extension on a nerve fell along which electrical impulses travel
What the myelin sheath
The insulating cover on the axon on a nerve cell, it’s speeds up the electrical impulse
What’s a xylem
Dead plant cells joined together into long tubes through which water flows during transpiration
What’s transpiration
The gradual release of water vapour from leaves to continue the pull of water up to them from the soil
What’s a phloem
Living cells that carry sugars made in photosynthesis to all cells of a plant
What’s translocation
The movement of Tigard made in photosynthesis from the leaves of plants
Tell me about red blood cells and how they a re adapted/specialised
They have a biconcave shape so more oxygen can be absorbed more quickly
They have no nucleus so they have more space to absorb oxygen
Tell me about sperm cells and how they are adapted/ specialised
Have a tail to help them swim towards ovum
Have a Relatively large amount of mitochondria to release energy from glucose during respiration
Tell about the nerve cell and how’s it’s adapted/ specialised
Have extensions (axons) to keep impulses moving quickly
Axon surrounded by myelin sheath acting like a plastic cost on a wide to insulate impulse
What’s the purpose of nerve cells
Nerve impulses (electrical signals) trvael along nerve cells in the nervous system
Tell me a bit about the nervous system
Made of 2 parts
central nervous system (Cns) which is made of brain and spinal cord
Them there the peripheral nervous system (pns) which is all other nerve cells that connect to Cns but spread out through body
Tell be about muscle cells and how they are specialised
They are specialised so they can contract and move different parts of the body
They have large numbers of mitochondria as muscle contraction requires a lot of energy
How many types of muscle are ther
3
Smooth, cardiac, skeletal
Tell me about root hair cells and how they are adapted
FOUND IN PLANTS
Have a small thin with one which pokes out into soil to increase surface area root is in contact with soil so more water and nutrients can be absorbed
Tell me about a xylem cell and how they are specialised
In plants
They are cells that from long tubes running along the stems of plants
They carry water and dissolved minerals from roots to other areas of plants(green areas)
In day for photosynthesises, xylem tubes are made of dead cells with no end walls and no content to hollow
Have reinforced side walls to support weight of plant - side walls are strengthened by lignin
Tell me about phloem cells and how they are specialised
They carry the glucose (as sucrose) made in photosynthesis from leave to other parts in cell sap(translocation)
Sugar used in respiration
Phloem cells are living
Have specialised end walls called sieve plates which have small holes
Phloem cells are arranged with xylem cells to form bundles which make up the veins Visible in a leaf
Tell me about cell differentiation
After generalised cells are formed they become specialised as an organism develops
Unlike animal cells, most plant cells retain ability to differentiate throughout their lifetime - we would not be able to take plant cutting without this
What’s an electron microscope
A microscope that uses electron beams in place of life to give higher mangification
What’s an electron
A negatively charged subatomic particle found in surrounded shells of nucleus in an atom
What’s resolution
The smallest distance between 2 separate points
What’s the eye piece lens
You look through this to see your sample- often 10x
What’s the objective lens
Usually 3 to choose from , 5x,10x,25x
What’s the stage
This holds the sample securely often using 2 metal clips
What’s the specimen
This is usually placed in a drop of water or stain on a microscope slide under a very thin glass cover slip
What’s the mirror
This reflects the light up through the sample and then the objective and eye piece lens into you eye, sometimes replaced by light source
What’s theCoarse focus
This quickly and easily moves the stage up and down to focus on sample
What’s the fine focus
This sensitively and slowly moves the stage up and down to allow you to make image her sharp
How do you work out goal magnification
Total magnification = magnification do eye piece X magnification of objective
What triangle do you need to remember ?
I
A x m
I on top of triangle
A + m on bottom
I= image size
A= actual size
M=magnification
Tell me about electron microscopes
They use electrons in place of light, the wavelength of electron can be up to 100,000 times smaller than that of visible light
So images can be taken at a lot Higher magnification
What are the 2 types of electron microscopes
Transmission electron telescope
Scanning electron telescope
Tell me about the transmission microscope
They fire a large been of electrons through a very thin slice of specimen
Not all electrons pass through the specimen, image only made of electrons that do
Tell me about the scanning microscope
Fire a smaller beam of electrons and scans across whole image but not all at same time, the electrons scatter from surface of sample and are detected tk make an image
Images can look three dimensional
What are images in electron micropscopes like
Black and white but some scurried colour then for a more striking look
Compare electron to light microscopes
Electron microscopes can magnify much more and have a greater resolution
The wavelength of light mean the maximum resolution of a light microscope is 200nm
1million manometres (nm) = 1mm
The electron microscope can resolve up to 2000 times closer than a light micropscope at a seperation of 0.1nm
