Cells Flashcards
Mitosis, cell cycle, cell organelles
Give the two types of molecule from which a ribosome is made.
RNA
and proteins
types of Eukaryotic cells:
Animal cells
and plant cells, Algal and fungal cells
They are bigger than prokaryotic cells.
Definition of eukaryotic cells
membrane bound organelles
Is much bigger than prokaryotic cells
contains DNA enclosed in a nucleus.
Organelles in both animal cells and plant eukaryotic cells.
Nucleus, nucleolus, nuclear pores, nuclear membrane, chromatin
RER rough endoplasmic reticulum
SER smooth …
Mitrochondria
Ribosomes
Golgi body
Cytoplasm
Centrioles and ventricles
Cell surface membrane made of phospholipids
What do Plant cells have that Animals don’t have?
Chloroplasts
Cellulose cell wall
Vacuole which has a partially permeable membrane
What do Algal cells have?
Nucleus, nucleolus, nuclear pore, nuclear membrane, chromatin
ribosomes
cell membrane and cell wall
cytoplasm
food vacuoles i.e. starch vacuole
mitochondria
chloroplasts
Golgi apparatus
centrioles
Fungal cells organelles?
ribosomes
bud star
cell wall made of chitin
cell membranes
nucleus, nucleolus, nuclear pores and membrane,
chromatin
Golgi apparatus
storage vacuole
RER AND SER
True or false
Fungal cells can be unicellular and multicellular?
True
Nucleus
The nucleus contains DNA
Nuclear membrane/envelope
Nuclear envelope: Double membrane. Controls entry and exit to the nucleus
Nuclear pores
Nuclear pores: allow passage of large molecules
Nucleoplasm
Nucleoplasm: makes up most of the nucleus. Within the nucleoplasm is chromatin (uncondensed genetic material)
Chromosomes
Chromosomes: linear DNA
Nucleolus
Nucleolus: Makes RNA and ribosomes
Mitochondria
and its structure too?
Double membrane
Cristae
Matrix
Mitochondria = aerobic respiration.
Produce ATP.
Double membrane: Controls what enters and exits
Cristae: Folded inner membrane providing a large surface area for the attachment of proteins involved in respiration
Matrix: It contains proteins, lipids, ribosomes and DNA allowing it to produce its own proteins.
Plasma membrane/ cell membrane
The plasma membrane- controls the entry & exit of substances into and out of the cell.
The plasma membrane is a phospholipid bilayer.
It has proteins embedded in it, which are able to move. So we call it a fluid mosaic.
RER –> ROUGH ENDOPLASMIC RETICULUM
– what is it surrounded by and what is its function?
This type of ER is studded with ribosomes.
Provides a large surface area for synthesis of proteins
Provides a pathway for the transport of materials, especially proteins, throughout the cell
Golgi body– Its function?
The Golgi Body modifies and packages molecules
Its functions are to:
Add carbohydrate to proteins to form glycoproteins
Produce secretory enzymes
Form lysosomes
Form vesicles
Lysosomes
Vesicles produced by the Golgi apparatus that contain enzymes.
They contain lysozymes that hydrolyse cell walls of certain bacteria
The functions are to:
Hydrolyse material ingested by phagocytes (white blood cells)
Release enzymes to the outside in order to destroy material around the cell
Digest worn out organelles so that the useful chemicals they made are re-used
Completely break down cells once they have died (autolysis)
Ribosomes function and structure
They are the site of protein synthesis
A ribosome are tiny organelles that either:
Float free in the cytoplasm
Attached to the endoplasmic reticulum (= RER)
There are two types depending on the cell they are found, in eukaryotic cells they are bigger (80S) than prokaryotes (70S)
Ribosomes have two subunits: a large and small unit, both contain ribosomal RNA.
What is the advantage to cells having mitrochondria?
Able to respire aerobically so are able to produce more ATP for release of more energy (for muscle contraction)
Cell wall in plants/fungi
function and what they are made of?
Consist of microfibrils of cellulose.
Thin layer, called middle lamella which forms a connected layer between adjacent cells.
It provides strength in order to prevent the cell from bursting
Allows water to pass through
Cell walls of fungi don’t contain cellulose but chitin instead
Chloroplasts function and structure:
Double membrane
Grana
Stroma
Contain DNA?
Chloroplasts are where photosynthesis take place.
They are made up of:
Double membrane controlling what goes in and out the chloroplast
Grana: Stacks of thylakoids containing chlorophyll. This is where the first stage of photosynthesis takes place
Stroma: fluid filled where the second stage of photosynthesis takes place
They contain both DNA and ribosomes to quickly manufacture proteins needed for photosynthesis
Vacuole.
Structure and function
A fluid filled sac bound by a single membrane called a tonoplast
Contains mineral salts, sugars, amino acids, wastes and pigments
They support plants by making their cells turgid
Pigments may be colourful to attract pollinating insectsV
Name two structures that are not present in animal cells but are in plant cells
Cellulose cell wall
chloroplast
vacuole, starch storage
Describe function of a chloroplast
Absorbs light and traps it
for photosynthesis
produces carbohydrates/lipids/ sugars/proteins.
Process of forming a functioning lysosome from the Golgi apparatus
Differentiation
The process by which cells become specialised for different functions
Cells may change to have… after differentiation
-Different shapes
-Different sizes
-Different no’s of organelles
-Change to produce different proteins
Cells definition
Are the basic structural and functional unit of life forms, formed using and contain many biological molecules
tissue definition
are a group of similar cells and they carry out a particular function
organs definition
Are different tissues working together and form organs
organ system definition
Different organs working together to form an organ system or collection of organs carrying out a specific physiological function more efficiently
7 types of tissue
Nervous tissue
epithelial tissue
thyroid tissue
glandular tissue
vascular tissue
connective and elastic tissue
organ types
Heart, liver, kidney, lung, small and large intestines, brain, pancrease
Organ system types
cardiovascular system,
respiratory system,
digestive system
neuromuscular
muscular skeletal
cell types
animal, plant, fungal, viral, algal, bacterial
What is a prokaryotic cell ?
and types of prokaryotic cells
NEED TO DO
viral and bacterial cell
DNA is not enclosed in nucleus and does not contain membrane bound organelles
Bacterial cell organelles
Murein Cell wall
Cell surface membrane
slime capsule
Flagella
Plasmids - extra but of circular DNA containing antibiotic resistance genes.
Ribosomes (70s)
Loop/circular DNA - not protein bound and free in the cytoplasm
Viral cell structure
capsid, attachment proteins,
lipid envelope, reverse transcriptase (Enzyme), matrix, genetic material (RNA)
What do Eukaryotic cells have that Prokaryotic don’t?
What 3 things do they both have?
What do just Prokaryotes have?
Nucleus, nucleolus, nuclear pores, nuclear membrane/envelope, chromatin
chromosomes
Chloroplasts
Ribosomes in Eukaryotic are 80s and prokaryotic are smaller – 70s
Golgi body
SER, RER, lysosomes, mitochondria
Both have cell wall (plants only from eukaryotic), ribosomes, DNA
Prokaryotic may have, flagella, slime capsule, plasmids
Describe how the structure of a Cholera bacterium is different to an epithelial cell in the small intestine?
(6 marks)
NEED TO DO
Cholera bacterium is prokaryotic
It does not have a nucleus/nuclear envelope and instead has DNA free in the cytoplasm as a loop of DNA
It has no membrane bound organelles/ no mitochondria or Golgi, or RER,SER
It has smaller 70s ribosomes not 80s ones
And may have a cell wall, plasmids, flagella and or slime capsule
How does it work – Optical microscope
Beam of light is condensed to create an image.
The long wavelength/beam of light passes up through the specimen, through lenses and reflected back onto the specimen.
adv light microscope
Can see colour
Can view living organisms
Hand held, easy to transport
disv light microscope
Poorer resolution due to light having a longer wavelength and therefore smaller organelles cannot be view cos are not visible
Cannot view SER, RER, Ribosomes, and lysosomes cos are all too small ( smaller than 0.2um)
How does it work – SEM – Scanning electron microscope
Specimen is in a vacuum
Scan electrons across surface of object knocks off electrons which are gathered by cathode to form images
ADV OF SEM
Can see external structures/ textures, the surface of organisms
3D
Is in colour
High resolution and magnification
DISV OF SEM
Cannot transport
requires training to read/use the microscope
lower resolution and magnification than TEM
cannot view living specimens and organisms
How does it work – TEM – Transmission electron microscope
Electron gun produces a beam of electrons which is focused by an electromagnet which are absorbed by a sample. Some electrons are absorbed ( these areas appear darker) and some areas don’t absorb electrons ( and appear lighter)
ADV OF TEM
Can see internal structures due to high mag and resolution due to having a shorter wavelength
DISV OF TEM
Image may contain artefacts (rips/tears/folds)
2D
cannot view living organisms cos a vaccum is required
Not in colour
very thin specimen needed
training required to use the microscope and it
cannot be transported
Magnification definition
How many times larger the image is compared to the object’s actual size
Resolution definition
Minimum distance between 2 objects, when they can still be viewed as separate.
This allows us to view with more clarity
Explain adv and limitations of using TEM to investigate cell structures?
(5 MARKS) NEED TO DO
Magnification formula
M = I /A
I = M x A
A = I /M
1m —1000m
…
1mm — 1000um
…
1um— 1000nm
…
1m — 100cm
…
Preparing a slide etc..
calculations with microscopes eye piece graticule
biological drawing rules
cell fractionation
cell cycle
exam ppq’s
