Unit 1.2 - Cell structure and organisation Flashcards
What does cell theory state?
That all organisms are composed of cells
What are cells?
The basic unit of life
What can organisms be (out of two options)?
Unicellular or multicellular
Examples of unicellular organisms
-Amoeba
-Bacteria
Examples of multicellular organisms
-Plants
-Animals
What’s the first cell that all cells came from?
The zygote
What’s important about the zygote?
It’s the first cell that all cells came from
What is an embryo all made up of?
Undifferentiated stem cells
Name a cell that contains all undifferentiated stem cells
Embryo
What do new cells arise from?
Pre-existing cells
What do specialised cells arise from?
Undifferentiated stem cells
What type of cell arises from undifferentiated stem cells?
Specialised cells
What type of cell arises from pre-existing cells?
New cells
Specialised cell
A cell with a particular function in the organism
Stem cell
A cell that has the potential to divide into any kind of specialised cell
Give two examples + brief descriptions of specialised cells
-Muscle cells are made up of short fibres that shorten and contract to move the joints
-White blood cells destroy pathogens
What has led to us understanding the ultra structure of cells?
Advances in microscopy
What has advantages in microscopy led to us being able to do?
Understand the ultra structure of cells
Ultra structure of a cell
What’s inside it
What is the big recent advance in microscopy?
The electron microscope
Why is an electron microscope better than a light microscope?
Magnifies much more
Name two types of microscope in order of strength of magnification, starting with the weakest
-Light
-Electron
Disadvantage of the electron microscope
No colours
How does the electron microscope work?
Electron gun fires them out into a vacuum so that it molecules don’t effect them
Name four relevant units of measurement to this unit and how we transfer between them
metre (m)
| x1000
\/
millimetre (mm)
|x1000
\/
micrometre (weird-ńm)
|x1000
\/
nanometre (nm)
Which unit is most commonly used with cells?
The micrometre
What is the number used to transfer between units in this unit?
1000
(multiply or divide when relevant)
How many metres is one nanometre?
10^-9m
What type of scale can we use to measure from pretty big things to tiny things?
Logarithmic scale
What’s a logarithmic scale?
A way of displaying data over a wide range in a compact way
Out of those 13 items on the logarithmic scale, place them in order from smallest to largest
(Check your notes)
What are all cells surrounded by?
A membrane made of phospholipids and proteins (thin in biological membranes)
What is thin in biological membranes?
The membrane of phospholipids and proteins surrounding the cells
Name the two types of cells
Eukaryotic and Prokaryotic
What are the features of eukaryotic cells?
-Have a nucleus
-Have membrane bound organelles
-Can include plant and animal cells
What type of cells are plant and animal cells?
Eukaryotic
Organelles
A specialised structure with a specific function in a cell
(Enclosed in the cytoplasm)
What do membranes provide?
-A large surface area for the attachment of enzymes involved in metabolic processes
-A transport system inside a cell
What are the advantages of having membrane bound organelles?
-Potentially harmful chemicals like enzymes are isolated
-Molecules with particular functions (chlorophyll, for example) can be concentrated in one area
Size of an average animal cell
10-30 micrometres (weird mm)
What is cytosol?
Fluid contained within the cytoplasm
I physically cannot think how to do this logically on a flash card - please just find an unlabelled animal cell on the internet and learn all of the bits - I know. I’m sorry.
Can’t help you here
Find and label a generalised plant cell on the internet - I know. I wish I could make it go away.
Sorry love
Size of a generalised plant cell
10 - 100 micrometres (weird mm)
What is leucoplast?
Starch storage in plant cells
What does the cell wall do to a cell?
Prevents it from collapsing/swelling due to its water levels
What’s the site of photosynthesis in a plant cell?
Chloroplast
What’s the difference between plant and animal cells?
Plant cells have additional organelles and structures
E.g - chloroplasts for photosynthesis
-cellulose cell walls for support + to maintain turgor pressure
-Vacuole
What do plants’ cellulose cell walls do?
Support the plant cell and help maintain turgor pressure
What do prokaryotic cells have?
No membrane bound organelles
Which membrane bound organelles do prokaryotic cells not have?
-Nucleus
-Rough endoplasmic reticulum
-Golgi apparatus
-Mitochondria
-Chloroplasts
Give 2 examples of prokaryotic cells
Bacteria and archaea
Again, I’m sorry, but find and label a bacteria cell
Yep
What’s the size of a typical bacteria cell?
1-10 micrometres (weird mm)
What are 2 things that you label on the prokaryotic cell that’s unique to them?
Plasmids and mesosome
What are the things you’d label on a bacteria cell and not on the plants and animal cells?
-Flagellum
-Capsule
-Mesosome
-Nucleoid
-Pilus
-Plasmids
What does the nucleoid of a bacteria cell contain?
A long, circular DNA molecule
What type of cell wall does bacteria have?
Mucopolysaccharide (Murein)
What does the mesosome on a bacteria cell do?
Increases the surface area of the membrane to allow reactions to take place
+ For respiration
What’s the capsule on a bacteria cell for?
Formed of slime, to protect the cell from its environment
What does the Flagellum on a bacteria cell do?
Allows bacteria to move through its environment
Wha do the ribosomes on a bacteria cell do?
Manufacture Proteins inside the cell
What do the plasmids in a bacteria cell do?
As small bits of circular DNA, they carry genes that can be transferred from one cell to another
Compare Eukaryotic and Prokaryotic cells
(First listed are Eukaryotic cell features)
-Larger cells (10-100micrometres v.s 1-10micrometres)
-Ribosomes are larger and bound to the rough endoplasmic reticulum v.s smaller and free in the cytoplasm
-Membrane bound organelles v.s none
-DNA contained to the Nucleus v.s free in the cytoplasm
-Nucleus has a double membrane v.s no nuclear membrane/double envelope
-No plasmids v.s plasmids
-Cell wall (when present) is composed of Cellulose or Chitin v.s composed of pectidoglycan (mucopolysaccharide)
-Mitochondria are used for aerobic respiration, not a mesosome v.s no Mitochondria, uses a mesosome (a folded region of the cell membrane) for aerobic respiration
Which cells are largest?
Eukaryotic (10-100 v.s 1-10 micro metres)
Compare the ribosomes in Eukaryotic cells and Prokaryotic cells
Euk - Larger and bound to the rough endoplasmic reticulum
Pro - smaller and free in the cytoplasm
Compare the DNA in Eukaryotic and Prokaryotic cells
Euk - contained to the nucleus
Pro - free in the cytoplasm
Describe the nucleus in Eukaryotic v.s Prokaryotic cells
Euk - Has a double membrane
Pro - No nuclear envelope (double membrane)
Describe the differences in cell wall for the Eukaryotic and Prokaryotic cells
Euk - Cellulose or Chitin
Pro - Pectidoglycan (muccopolysaccharide)
Describe how Eukaryotic v.s Prokaryotic cells respire
Euk - Mitochondria are used (no mesosome)
Pro - No mitochondria, uses a mesosome (a folded region of the cell membrane)
What do Prokaryotic cells have that Eukaryotic cells don’t?
Plasmids and a mesosome
What do Eukaryotic cells have that Prokaryotic cells don’t?
Membrane bound organelles ( e.g - mitochondria)
What’s an appropriate way to describe a virus?
A complicated chemical
What are viruses to be referred to as?
Particles
Why are viruses not referred to as cells?
They don’t do the things that other living organisms do, like respire or reproduce
What kind of things do other living organisms do that viruses don’t?
Respire and reproduce
How do viruses reproduce?
Have to enter Prokaryotic/Eukaryotic cells and use their processes
What’s the average size of a virus particle?
0.1 micrometres (weird mm)
What are the three features to label on a virus particle?
-Nucleic acid (DNA/RNA)
-Surface proteins
-Protein coat (capsid)
What do the surface proteins of a virus particle help it do?
Gain entry into a host cell
Name for the protein coat of a virus particle
Capsid
What do viruses tend to be?
Very variable
Name 5 types of virus
-Adenovirus
-HIV
-Rabies virus
-Bacteriphage
-Influenza virus
Which type of virus is used in genetic engineering to transfer genes?
Adenovirus
What’s the Adenovirus used for?
Used in genetic engineering to transfer genes
What type virus can be transferred from mammals to humans? Why is this unusual?
The Rabies virus, as viruses usually only infect 1 species
Why is the Rabies virus unusual?
As it can be transferred from mammals to human and viruses usually only infect 1 species
Which virus infects bacteria?
Bacteriophage
What does bacteriophage do?
Infects bacteria
What do we know if the host cell is bacteria?
That the virus is bacteriophage
How will we know if the virus is bacteriophage?
The host cell is bacteria
Which type of virus causes the flu?
Influenza virus
What does the influenza virus do?
Causes the flu
How do viruses work?
- The viral genome enters the host cell and injects genetic material, instructing the cell to start making new viruses;
- Viral genome is replicated and transcribed - DNA is copied and used to make virus proteins (DNA - mRNA) : the virus has taken over the cell ;
- Viral mRNAs are translated and proteins processed - virus particles are assembled;
- Particles assemble inside the host, then burst or bud to exterior, destroying the cell - free particles in the tissue or Environment, ready to infect new cells
Which stage in how viruses work are Scientists still pretty uncertain about?
Part 3, where the virus mRNAs are translated and proteins processed (virus particles are assembled)
What type of process is viral replication?
Genetic
Functions of the nucleus
-Contains DNA (made in the ribosomes) which codes for/controls protein synthesis
-DNA replication occurs here
-Transcription produces mRNA templates
Size of the nucleus
4 micro metres
Draw and label a nucleus
(Check notes)
What is there linking the nuclear envelope and the rough endoplasmic reticulum?
Tubular continuity
What makes up the nuclear envelope of a nucleus?
Inner and outer nuclear membrane
Function of nuclear pores
Allow the transport of mRNA and ribosomes out of the nucleus
Function of nuclear envelopes/double membranes
Separates the contents of the nucleus from the cytoplasm
What’s another phrase for the nuclear envelope?
The double membrane
Chromatin function
Condenses before cell division to form chromosomes
How does chromatin work?
Wraps around histone protein molecules in the DNA as a way of organising the DNA in the nucleus. It can unwind to form proteins.
What type of protein does chromatin wrap itself around to organise the DNA in the nucleus?
Histone protein
Nucleolus function
Produces rRNA, tRNA and ribosomes
What is produced by the nucleolus?
-rRNA
-tRNA
-ribosomes
How do we recognise the nucleolus under the microscope?
Large dark patch
How does the rough endoplasmic reticulum get its name?
When seen under the electron microscope, the ribosomes on the surface can be seen
What IS the rough endoplasmic reticulum?
A system of parallel double membranes
Rough endoplasmic reticulum function
-Packaging and storing proteins (modifying them)
-Producing transport vesicles which merge to form the Golgi body
Draw and label the rough endoplasmic reticulum structure
(Check notes)
What do you call the gaps between the parallel rough endoplasmic reticulum membranes and what is their function?
Cisternae, which put the protein into 3D form
What do the cisternae do?
Put the protein into 3D form
What happens after a ribosome has made a protein?
It’s fed into the cisternae and fed throughout the cell
What makes the primary protein structure?
Ribosomes
How is a protein fed throughout a cell?
-Membranes arranged into sheets with cisternae in between
-Ribosomes make proteins
-Protein is fed into the cisternae
-Cisternae feeds the protein throughout the cell
Smooth endoplasmic reticulum function
Produce, package and transport steroids and lipids
What does the smooth endoplasmic reticulum NOT produce, package and transport?
Proteins
What does the smooth endoplasmic reticulum not have?
Ribosomes
What structures are present on the smooth endoplasmic reticulum?
-Membrane
-Cisternae (gaps)
What’s an accurate description of the Golgi body?
Very dynamic - lots happening
Functions of the Golgi body
-Packaging proteins for secretion from the cell
-Modification of proteins (e.g - adding carbohydrate chains to form glycoproteins)
-Producing lysosomes and digestive enzymes (tertiary structure)
Secretion
Where substances are discharged from the cell, in the example of the Golgi body, it’s proteins
What travels with the protein which it’s transporting to the Golgi body?
Vesicle
3 levels within the Golgi body that allows secretion to take place
-Cis cisterna
-Medial Golgi
-Trans cisterna
What does a vesicle do?
Travels and merges with the Golgi body with the protein that its transporting
What do vesicles fuse with?
The plasma membrane
What happens at the trans cisterna of the Golgi body?
-Proteins are modified - processed and packaged into vesicles, and parts bud off to form capsules that break off
-This ensures that proteins are delivered to the correct place
What do we mean when we say that proteins are ‘modified’ by the trans cisterna?
Processed and packaged into vesicles before breaking off as capsules
What are proteins synthesised by and where?
Ribosomes on the rough endoplasmic reticulum
How does the rough endoplasmic reticulum form vesicles?
Made of membrane, which can pinch off of the reticulum to form a vesicle
What forms a vesicle for secretion?
The rough endoplasmic reticulum
What do vesicles move towards by the Golgi body and why?
The cell membrane to release content
Which type of vesicles do not undergo secretion and why?
Some stay within the cytoplasm of the cell as they have specific functions here
Where do vesicles that do not undergo secretion stay?
In the cytoplasm of the cell
Ribosomes function
-Protein synthesis
-Primary protein structure is formed here
What type of protein structure is formed by ribosomes?
Primary protein structure
What do ribosomes consist of?
A small and a large subunit
How big are ribosomes?
About 10nm - incredibly small, more like big molecules
What can ribosomes be compared to and why?
Big molecules, as they’re so small (d= 10nm)
How does the ribosome know what protein to make?
-Instructions to make proteins are fed through, written on am mRNA molecule in the nucleus.
-Tells the ribosome, like a code, what type of protein to make
What are the instructions for protein synthesis written on for ribosomes?
mRNA molecules in the nucleus
What are mRNA molecules in the nucleus responsible for?
Being fed through the ribosomes, giving instructions of what type of proteins to make
Mitochondria function
ATP synthesis by aerobic respiration
What is the mitochondria vital for?
All cells that respire aerobically
What do cells respire anaerobically through?
The cytoplasm
What do cells respire aerobically through?
The mitochondria
Draw and label a mitochondria
(Check notes)
Where do lots of respiration reactions happen within the mitochondria?
In the matrix
Where is the site of ATP synthesis in the mitochondria?
Storked particles
What are storked particles in the mitochondria?
-Site of ATP synthesis
-Complex particles, imbedded in inner membrane
Where are storked particles to be found in the mitochondria?
Imbedded in the inner membrane
What are we seeing when we see the mitochondria through a microscope?
A thin slice through the organelle
What does the endsymbiont hypothesis state?
That mitochondria (and chloroplasts) may have been free-living, unicellular organisms millions of years ago
What’s the name of the hypothesis that states that mitochondria may have been free-living, unicellular organisms millions of years ago?
Endosymbiont hypothesis
What’s the proof for the endosymbiont hypothesis in the mitochondria?
-Circular DNA (similar to prokaryotic cells)
-Smaller ribosomes than the rough endoplasmic reticulum + cytoplasm (similar to prokaryotic cells)
-Fairly large (0.8 micro metres diameter)
How big are the mitochondria?
A diameter of around 0.8 micro metres
What type of cells does the mitochondria (and chloroplasts!) share similar factors with and what are they? What did this lead to (which is?)?
-Prokaryotic cells
-Circular DNA
-Smaller ribosomes than the rough endoplasmic reticulum + cytoplasm
=endosymbiont hypothesis
(The hypothesis that the mitochondria may have been free-living unicellular organisms millions of years ago)
What type of ribosomes does the mitochondria have?
Small, 70s ribosomes
What shape does the mitochondria have and why is this effective?
Cylindrical
-Larger surface area to volume ratio than a sphere
-Reduces diffusion distance between the edge and the centre
-Efficient aerobic respiration
What does the fact that the mitochondria is cylindrical mean for it?
Bigger surface area to volume ratio
-Reduces diffusion distance between the edge and centre for efficient aerobic respiration
What decreases and increases due to the mitochondria bing cylindrical in shape?
Decreases - Diffusion distance between the edge and the centre
Increases - Efficiency of aerobic respiration
What’s the distance between the edge and the centre of the mitochondria known as?
The diffusion distance
What deceases a mitochondria’s diffusion distance?
Being cylindrical in shape
What are eukaryotic cells usually doing if they divide?
Growing and replacing old cells
What are prokaryotic cells doing if they divide?
Creating entire new cells
Why is it important for plant cells to have their cellulose cell walls?
To maintain turgor pressure to avoid bursting
What do the lysosomes contain?
Powerful digestive enzymes to break down worn out organelles or cells
What happens to cells at the end of their lifespans?
Programmed cell death
How does programmed cell death work?
Cell produces many lysosomes, which burst open, release their enzymes and digest the whole cell
What actually ARE lysosomes?
Vesicles
What’s a vesicle?
Capsules formed from a membrane that contain something
What do the lysosome vesicles contain?
Digestive enzymes
What type of programmed cell death occurs with mutations?
Spontaneous
If programmed cell death happens spontaneously, what form does it take?
Mutations
2 examples of programmed cell death happening spontaneously in the form of mutations
-Metamorphosis- tails of tadpoles are broken down
-Embryos fingers are released when a membrane is broken down
What do the digestive enzymes in lysosomes do?
Break down worn out organelles or cells
What can be done with worn out organelles?
Digested by the powerful digestive enzymes of lysosomes and can be re-used
Where do vesicles form and how does this form a lysosome?
Vesicles form from the Golgi body and bud off to form a lysosome
How do phagocytes use lysosomes?
To digest engulfed bacteria
What do phagocytes use to digest engulfed bacteria?
Lysosomes
What do centrioles do?
Form the spindle during cell division
What does the spindle of a centriole do?
Connect chromosomes and pull them apart
What connects to chromosomes and pulls them apart in centrioles?
Spindle
What are centrioles not present in?
Higher plant cells
What isn’t present in higher plant cells?
Centrioles
Centrioles shape
Cylindrical
What are centrioles formed from?
Microtubules
How many microtubules are centrioles formed from?
9 groups of 3
Examples of cell division
Mitosis and meiosis
What does the vacuole do?
-Contains cell sap and stores solutes such as glucose
-Swells due to osmosis for turgidity
What does the vacuole contain?
Sell sap
Give an example of a solute that the vacuole stores
Glucose
Sell sap
Solution containing sugars and amino acids
What happens to the vacuole if it has a low concentration of water?
Water moves in due to osmosis
When is a cell turgid?
When it swells with water and is as full as it can be
What is a cell when it’s as full as it can be with water?
Turgid
What’s the name of the membrane around the vacuole?
Tonoplast
Tonoplast
Membrane around the vacuole
What does the vacuole do to other organelles within the cell and why?
Pushes the cytoplasm and organelles towards the edges of the cell due to it filling the cell.
What do chloroplasts do?
Contain photosynthetic pigments which trap light energy for photosynthesis
What do chloroplasts contain?
Photosynthetic pigments
What do chloroplasts take in? Describe these
H20 and C02 - simple, inorganic compounds
What type of compounds are H20 and C02 (which are taken in by the chloroplasts)?
Simple and inorganic
What’s the product of photosynthesis in chloroplasts?
Carbohydrates like glucose
Stroma
Fluid that includes enzymes for catalysing photosynthesis reactions in chloroplasts
Which part of a cell are the grana on and what are they?
In chloroplasts, formed from little sacks of membrane known as Thylocoids
What are the little sacks of membrane that form the grana on chloroplasts known as?
Thylocoids
What are the starch grains on chloroplasts?
Carbohydrates produced through photosynthesis by the plant
What surrounds the chloroplast?
Chloroplast envelope (double membrane)
Draw and label a chloroplast
(Check notes)
What can chlorophyll be seen under?
An electron microscope
What do chloroplasts have that make them similar to prokaryotic cells?
-Circular DNA
-Ribosomes similar to the mitochondria
Which part of the cell also falls under the endosymbiont hypothesis and why?
Chloroplasts, as they have ribosomes like the mitochondria and a circular DNA
What type of cells is the plasmodesmata seen in?
Plant cells
What does the plasmodesmata do?
-Connects cells via cytoplasm filled canals, which pass through cell walls
-Allow transport of materials between cells via the symplastic pathway
What type of materials does the plasmodesmata allow transport of between cells?
Sugar and other substances
What type of pathway allows transport of materials between cells in the plasmodesmata?
Symplastic pathway
Draw and label the plasmodesmata
(Check notes)
Draw and label a cell wall
(Check notes)
What does the cell wall do?
-Gives mechanical strength due to the high tensile strength of cellulose microfibrils
-Transports solutes via the apoplastic pathway
-Cell to cell communication via the plasmodesmata
What does the cell wall allow to move in and out through itself?
-Water
-Dissolved ions
How does the transport of solutes happen in the cell wall?
Apoplastic pathway
Apoplastic pathway
Allows the transport of solutes in the cell wall
Symplastic pathway
Allows transport of materials between cells in the plasmodesmata
Why does the cell wall have a high tensile strength?
Due to the cellulose microfibrils
What do cellulose microfibrils give the cell wall?
A high tensile strength
Via what does cell to cell communication happen?
The plasmodesmata
What’s transported via the apoplastic pathway in the cell wall?
Solutes
What can be re-used from the lysosome?
Worn out organelle molecules that have been digested by the lysosome
What are cells organised to form in multicellular organisms?
Tissues
Organs
Tissues
Groups of similar cells working together, organised to carry out 1+ function within the body
3 examples of tissues in animals
Epithelium, Skeletal muscle, Cartilage
3 examples of tissues in plants
Xylem, Phoelem, Parenchyma
What are the Xylem, Phoelem and Parenchyma?
Tissues found in plants
Organs
Distinct parts of an organism that are specialised to perform 1+ function
4 examples of organs in animals
Eyes, Kidneys, Lungs, Heart
4 examples of organs in plants
Roots, stem, leaf, flower
What do organs usually contain in terms of tissues?
Several different tissues
Which tissues does the heart contain?
Cardiac muscle, nervous tissue, connective tissue
Organ systems
Involve a number of different organs working together to perform a common function
Example of an organ system
The digestive system -
Includes the stomach, intestines, liver and pancreas
How do cells form a tissue?
Cells adjacent each other in the embryo often differentiate in the same way to form a tissue
What are the three types of tissue we must learn, and what are they in?
-Epithelial tissue
-Muscle tissue
-Connective tissue
(In Mammals)
Epithelial tissue
Forms a continuous layer, covering or lining the internal or external surfaces of the body
Does the epithelial tissue include blood vessels?
Nope
Does the epithelial tissue have nerve endings?
Possibly
In what type of tissue do cells sit on something (what?) and what is this made of?
In the Epithelial tissue, cells sit on a basement membrane, made of collagen and protein
What is the basement membrane in epithelial tissue made up of?
Collagen and protein
What does the basement membrane, made of collagen and protein, vary in?
Shape and complexity
What type of functions (2) do epithelial tissues normally have?
Protective or secretary
What are the three types of epithelial tissue?
Cuboidal
Ciliated
Squamous
What does the cuboidal epithelium do?
Lines kidney tubules and the small intestine
What are the small intestine and kidney tubules lined by?
Cuboidal Epithelial tissue
How do we recognise simple and stratified cuboidal images?
One layer of cells - simple
2 layers of cells - stratified
What shape cells make up the cuboidal epithilum?
Cuboidal
What is cube shaped within the cuboidal epithilum?
Cells
What does the ciliated epithilium do?
-Composed of cells which transport substances like mucus in the bronchi and ova in the Fallopian tubes
-Cilia move and sweep substances along
What does cilia do?
Move and sweep substances along
Two examples of substances transported by the ciliated epithilium
Mucus in the bronchi
Ova in the Fallopian tubes
Cells which make up which type of tissue are substances like mucus in the bronchi and ova in the Fallopian tubes transported by?
The ciliated epithilium
What shaped cells are in the ciliated epithilum?
Columnar
What is columnar shaped in the ciliated epithilium?
The cells
Which type of tissue has columnar shaped cells?
Ciliated epithilum
Which type of tissue has cube shaped cells?
Cuboidal epithilum
What are the three different types of ciliated epithilum and how do we differentiate between them in diagrams?
-Simple columnar: Simple columns (microvilli on top)
-Stratified columnar: columns more split off
-Pseudostratified ciliated columnar: More wavey sort of columns
What do you call the little hairs on the top of the pseudostratified ciliated columnar epithilum?
Microvilli
What is the squamous epithilum?
Consists of flattened cells on a basement membrane
What does the squamous epithilum form?
-The walls of the alveoli
-Line Bowman’s capsule in the kidney nephron
What do all three of the types of epithilal tissue we’re looking at (cuboidal, ciliated and squamous) include?
A basement membrane
Does the squamous epithilum include a basement membrane?
Yes - all three epithelial tissue types do
What type of tissue forms the walls of the alveoli and line Bowman’s capsule in the kidney nephron?
Squamous epithilum
What are the types of squamous epithilum and how do we recognise them in diagrams?
-Simple squamous: one layer of cells
-Stratified squamous: multiple layers of cells
What are the three main types of muscle tissue and what do they all have?
Skeletal
Smooth
Cardiac
(Different structures and functions)
What do skeletal muscle tissues do?
Are attached to bones - move the skeleton
What is the skeletal muscle tissue made up of?
Bands of long cells - fibres
3 features of the fibres within skeletal muscle tissue
Can contract powerfully
Tire easily
Can choose whether or not to contract them - voluntary muscles
What type of muscle can we contract powerfully (yet they tire easily), and can we choose whether or not to contract them (voluntary muscles) and why?
Skeletal (has bands of long cells known as fibres)
What are skeletal muscles as a result of the fact that they have bands of long cells that you can choose whether or not to contract?
Voluntary muscles
Fibres
Bands of long cells in the skeletal muscle tissue
What are the bands of long cells in the skeletal muscle tissue known as?
Fibres
What can the skeletal muscle tissue also be referred to as and why?
Striped or striated muscle as it forms a striped pattern under the microscope
What type of tissue is often described as striped or striated and why?
The skeletal muscle tissue, as it forms a striped pattern under the microscope
Draw and label the skeletal muscle tissue
(Check notes)
What are the thick and thin filaments within skeletal muscles tissue?
Actin - thin filament
Myosin - thick filament
Actin
Thin filament in skeletal muscle tissue
Myosin
Thick filament in skeletal muscle tissue
What are actin and myosin?
Thin and thick filaments within the skeletal muscle tissue
What does the smooth muscle tissue consist of?
Individual spindle shaped cells that can contract rhythmically
What shape are the cells within smooth muscle tissue?
Spindle shaped
How do the cells contract within smooth muscle tissue?
Rhythmically, but less powerfully than skeletal muscle tissue
Which cells contract most powerfully - Skeletal or Smooth muscle tissue cells?
Skeletal
Where can smooth muscle tissue be found?
Skin
Walls of blood vessels
Digestive and respiratory tracts
What type of tissue can be found in the skin, the walls of blood vessels and in the digestive and respiratory tracts?
Smooth muscle tissue
Can you control smooth muscles? What does this mean?
No, they’re involuntary muscles
Are the skeletal and smooth muscle tissues voluntary or not? What does this mean?
Skeletal - Voluntary (can choose whether to contract them)
Smooth - Involuntary (cannot choose whether to contract them)
What is another name given to the smooth muscle tissue and why?
Unscripted or unstriated muscle as it does not display a striped pattern under the microscope
Which tissue is often described as unstriped or unstriated and why?
Smooth muscle tissue as it doesn’t form a striped pattern under the microscope
Draw and label a smooth muscle tissue
(Check notes)
What shaped nuclei does the smooth muscle tissue have?
Cigar shaped
Where is the cardiac muscle tissue found?
Only in the heart
What are the structures and properties of cardiac muscle tissue similar to?
In between skeletal and smooth muscle
Structures/properties of the cardiac muscle tissue that are similar to skeletal muscle tissue
Have stripes
What feature do both the skeletal and cardiac muscle tissues share?
Have stripes
What structures/properties do the cardiac and smooth muscle tissues share?
Lack the long fibres of the skeletal muscle
Doesn’t tire
Contract rhythmically, without stimulation form nerves or hormones
What does the smooth and cardiac muscle tissue not require from nerves or hormones?
Stimulation to contract rhythmically
From what do the smooth and cardiac muscle tissues not require stimulation from?
Nerves and hormones
What CAN nerves and hormones do within cardiac muscle tissue?
Modify their contractions, although they aren’t required to stimulate the rhythmic contraction in the first place
What does the connective tissue do?
Connect OR support OR separate tissues and organs
What does the connective tissue contain?
Elastic and collagen fibres in an extracellular fluid or matrix
What are the elastic and collagen fibres within the connective tissue found in?
Extracellular fluid or matrix
Extracellular fluid or matrix
Contains the elastic and collagen fibres in the connective tissue
What is between the fibres within the connective tissue?
Fat storing cells (adipocytes) and cells of the immune system
Where are the adipocytes (fat storing cells) and cells of the immune system within the connective tissue?
Between fibres
Adipocytes
Fat storing cells found between fibres in the connective tissue
Fat storing cells found between fibres in the connective tissue
Adipocytes
Function of the connective tissue
Support
Packing
Defence
Repair
7 examples of connective tissue
Areolar tissue
Collagen
Ligaments
Adipose tissue
Blood
Lymph
Cartilage
Where are the epithelium, skeletal muscle and cartilage tissues found?
In animals
Areolar tissue:
What type of tissue is it?
Where is it found?
What is its function?
Connective tissue
Under the skin
Connects organs and tissues together
Collagen function and type of tissue
Forms tendons which connect muscles to bones, connective tissue
Tendons
Formed by the collagen connective tissue, connect muscles to bones
Ligaments function and type of tissue
Connect bones and elastic tissues, connective tissue
Adipose tissue
What is it composed of?
What type of tissue is it?
Where is it found?
Function?
Fatty cells
Connective tissue
Just under the skin and around organs
Energy store, protects delicate organs an thermal insulator
Types of tissues found in the stomach
Smooth muscle tissue
Loose connective tissue
Nervous tissue
Blood
Columnar epithilum
Compare the presence of the plasma membrane across bacteria, animal and plant cells
All include it
Compare the presence of the nuclear membrane across bacteria, animal and plant cells
In plant and animal cells, not bacteria
Compare the presence of membrane bound organelles (e.g - mitochondria, endoplasmic reticulum) across bacteria, animal and plant cells
In animal and plant cells, not bacteria cells
Compare the presence of ribosomes across bacteria, animal and plant cells
Bacteria - small, 70s free in the cytoplasm
Animal and plant - large, 80s free in cytoplasm and attached to rough endoplasmic reticulum
Compare the presence of vacuoles across bacteria, animal and plant cells
Bacteria - smaller than eukaryotic cell vacuoles (smaller cell)
Animal - small and temporary
Plant - Large, permanent vacuole surrounded by a Tonoplast membrane
Examples of membrane bound organelles
Mitochondria, endoplasmic reticulum
What is the Bacteria cell’s large permanent vacuole surrounded by?
A Tonoplast membrane
Compare the presence of chloroplasts across bacteria, animal and plant cells
Only in plant cells
Compare the presence of the mesosome across bacteria, animal and plant cells
Only in bacteria cells
Compare the presence of centrioles across bacteria, animal and plant cells
Only in animal cells
Compare the presence of DNA across bacteria, animal and plant cells
Bacteria - circular, not associated with histone proteins, loose in the cytoplasm
Plant and animal - linear, associated with histone proteins to form chromosomes, found in the nucleus
Compare the presence of the cell wall across bacteria, animal and plant cells
Bacteria - made of peptidoglycan
Animal - X
Plant - made of cellulose
What do virus particles not do that causes us not to refer to them as cells?
-Grow
-Respire
-Reproduce (invade host cells and use their metabolic processes to produce more virus particles)
What do virus particles not have that causes us not to refer to them as cells?
-Cell membrane
-Cytoplasm
What’s the nucleolus made from?
Condensed chromatin
What does the rough endoplasmic reticulum transport to the Golgi body?
Polypeptides
What type of vesicles will eventually release their contents to the outside of the cell?
Secretory vesicles
Secretory vesicles
Vesicles that will eventually release their contents to the outside of the cell
What are the outer membranes of two adjacent cells?
Plasma membranes
What could be responsible for the different appearances in mitochondrion?
-Could have been cut in different places
-Self-replication: different sizes and ages
What are two ways the mitochondria has adapted to perform its function?
Cylindrical shape - larger surface area to volume ratio than a sphere - reduces diffusion distance between the edge and the centre for efficient aerobic respiration
Folded membranes (Cristae)
What are processed in the Golgi bodies?
Proteins and lysosomes
Name a tissue which contains large numbers of mitochondria
Skeletal muscle tissue
Name the two molecules found in chromosomes
DNA and histone proteins
Name two forms of chromatin
Heterochromatin
Euchromatin
What are heterochromotin and euchromatin?
Forms of chromatin
Which form of chromatin contains DNA with active genes?
Euchromatin
What is the outer membrane of two adjacent cells?
Plasma membrane
Plasma membrane
Phospholipid bilayer with proteins embedded in it and carbohydrates embedded in the surface
What’s embedded in the plasma membrane and what’s on the extracellular surface?
Embedded - proteins
Extracellular surface - carbohydrates
What type of surface does the plasma membrane have?
Extracellular
Plasma membrane function
-Selectively permeable barrier between internal and external environment of the cell
-(Only in Eukaryotes) - cell recognition
What function does the plasma membrane have that’s only in Eukaryotic cells?
Cell recognition
In what type of cells only does the plasma membrane have the function of cell recognition?
Eukaryotes
Cytoplasm
Mainly fluid (the cytosol), which contains dissolved substances and enzymes
The site of many cell reactions (e.g - anaerobic respiration)
What is cytoplasm mainly?
Cytosol
What is both a nucleotide and a plasmid?
Circular DNA free in the cytoplasm
Nucleoid function
Carries bacterial genetic code
Plasmids function
Carry additional genes (e.g - antibiotic resistance genes) and can be passed from 1 bacterium to another
Example of an additional genes that plasmids can carry
Antibiotic resistance genes
Pectidoglycan cell wall
Rigid layer composed of sugars with amino acid side chains
Beta bonding forms cross links between molecules of pectidoglycan - microfibrils
Peptide bonds create stronger links than hydrogen bonding in cellulose
What is the pectidoglycan cell wall composed of?
Sugars with amino acid side chains
Type of bonding in the pectidoglycan cell wall
Beta
Which is strongest - pectidoglycan or cellulose cell walls? How so?
Pectidoglycan - peptide bonds create stronger links than hydrogen bonding in cellulose
Pectidoglycan cell wall function
-Determines the shape of the bacterial cell
-Protection form toxic compounds and osmotic effects
Nucleus:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic cells only
Nucleolus:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic cells only
Rough endoplasmic reticulum:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic cells only
Plasma membrane:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Both prokaryotic and eukaryotic cells
Cytoplasm
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Both prokaryotic and eukaryotic cells
Nucleoid and plasmids:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Prokaryotic cells only
Pectidoglycan cell wall:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Prokaryotic cells only
Smooth endoplasmic reticulum:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic cells only
Golgi body:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic cells only
Ribosomes:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic and Prokaryotic cells
Mitochondria:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Eukaryotic cells only
Centrioles:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Animal cells only
Vacuole:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Plant cells only
(small and temporary in animal cells)
Chloroplasts:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Plant cells only
Plasmodesmata:
Is it present in Prokaryotic, Eukaryotic, both, specifically plant only or specifically animal only cells?
Plant cells only
List 5 organ systems
The digestive system
The nervous system
The endocrine system
The cardiac system
The immune system
Give an example of an epithilium tissue
the skin
What is cilia?
Protein forms from microtubules
What does mucus in the bronchi do?
Catches dust particles and moles towards the mouth so as not to reach the alveoli and cause infection
What does the ova in the Fallopian tubes do?
- Moves the eggs towards the womb
-After fertilisation, the early embryo is carried towards the uterus by the cilia
Describe the squamous layer and give a reason for why it’s like this
A very thin layer in order to have a short distance for oxygen to diffuse in exchanges
What type of epithelium is skin?
Stratified squamous epithilium
What type of epilithial tissue forms the capillaries?
Simple squamous
Describe the skin on the outer surface of the skin and what happens because of this
Dead, so its replaced by ew cells from the age of the epithilum
What’s the name for muscle cells?
Myocytes
Myocytes
Muscle cells
How many nuclei are there per cell of the smooth muscle tissue?
1
What type of muscle tissue makes up the walls of the oesophagus?
Smooth muscle tissue
How does food reach our stomach? What’s the name of the process?
-Walls of the oesophagus are made up of smooth muscle tissue (involuntary muscles!)
-A wave of attraction known as peristalsis from the smooth muscles, pushing food towards the stomach
What type of tissue makes up blood vessels and how do they work?
Smooth muscle
Relax to increase diameter to control the movement of blood
What could the cardiac muscle cells do outside the body and what do we call this?
Could contract by themselves in the right conditions outside of the body due to their internal impulse to contract, making them myogenic
Myogenic
Cardiac muscle cells’ internal impulse to contract, even if outside of the body
Why does the skeletal muscle tissue contain multiple mitochondria?
For ATP synthesis
What are myocytes made out of?
Myofibrils
Myofibrils
Make up myocytes
What are actin and myosin?
Protein filaments in the skeletal muscle tissue
Protein filaments in the skeletal muscle tissue + descriptions
Actin (thin), Myosin (thick)
What actually causes a muscle to contract?
Protein filaments are interwoven together - can slide over each other for the muscle to contract
Describe the nuclei in the cells of skeletal muscle
Multi-nucleated: More than one nucleus per cell
Multi-nucleated
Definition and example
More than one nucleus per cell
Cells of the skeletal muscle tissue
Where are the 5 different tissues in the stomach found?
Smooth muscle, loose connective, nervous and blood - Walls
Columnar epithelium - Inner lining
What are the 6 functions of the cell surface membrane/the plasma membrane?
-The boundary that separates the living cell from its non-living surroundings
-Controls which substances pass into and out from the cell
-Cell recognition
-Controls the uptake of nutrients
-Allows waste products to pass out of the cell
-Is responsible for secreting substances such as enzymes and glycoproteins
What type of substances is the plasma membrane responsible for secreting?
Enzymes and glycoproteins, for example
Another word for the plasma membrane
Cell surface membrane
What is the plasma membrane made up almost entirely from?
Phospholipids and proteins
What can the phospholipids within the plasma membrane do?
Form bilayers, with one sheet of phospholipid forming over another
What forms the basis of membrane structure?
The phospholipid bilayer
What does the phospholipid bilayer form?
The basis of membrane structure
What does the phospholipid bilayer of the plasma membrane allow to enter and leave the cell?
Lipid soluble (non-polar) molecules
What can lipid soluble (non-polar) molecules do within the cell? Why?
Enter and leave the cell due to the phospholipid bilayer
What does the phospholipid bilayer prevent from entering and leaving the cell?
Water soluble (polar) molecules
What can water soluble (polar) molecules do to a cell? Why?
They cannot enter and leave the cell due to the phospholipid bilayer
What type of molecules are lipid soluble?
Non-polar
What type of molecules are water soluble?
Polar
What’s a test we could do to see the phospholipid bilayer working within the cell membrane?
-Add a water soluble stain
-Hydrophillic part would accept the stain
-Each side of a hydrophobic layer would reject the stain
What is between the cell membranes between cells?
Intercellular space
Intercellular space
Between cell membranes between cells
What’s the usual diameter of a cell membrane?
7-8nm
Name two differences between the Golgi Body and the rough endoplasmic reticulum
Golgi body
-Packaging + assembling glycoproteins
R.E.R
-Storing + protein synthesis (has ribosomes)
What’s similar between the Golgi body and the rough endoplasmic reticulum?
Both involved in transport
Compare the presence of plasmids across prokaryotic and eukaryotic cells
Eukaryotic - no plasmids
Prokaryotic - may contain plasmids
What are the subunits on a ribosome?
Small 30s, and large 50s
What attachment sites does a ribosome have?
mRNA
2 tRNA
Draw and label a ribosome
(check notes)
Cristae
Folded membranes
Folded membranes
Cristae
Draw and label the golgi body
(check notes)
Cristae
Folded membranes of the mitochondrion
Cisternae
Flattened membrane of the endoplasmic reticulum and Golgi body
Describe the membrane of Cristae
Folded
Describe the membranes of cisternae
Flattened
What do Cristae appear in?
The mitochondria
What do cisternae appear in?
The endoplasmic reticulum and Golgi body
What is the difference between Cristae and cisternae?
Cristae - folded membranes of the mitochondrion
Cisternae - flattened membrane of the endoplasmic reticulum and Golgi body
What do we always say for the structures in the trachea?
Cilia, not microvilli (no microvilli in the trachea)
What doesn’t have microvilli?
The trachea
Which other parts of the cell apart from the nucleus contain DNA?
mitochondria and chloroplasts
Nucleus vs nucleolus
Nucleus - sub-organelle of the nucleus
Nucleolus - membrane bound organelle
What’s the difference between simple and stratified epithelial tissue?
Simple - 1 single cell layer
Stratified - more than one layer
What are he major biochemical elements present in ALL viruses?
Protein
Nuclei acid
What are the biochemical components protein and nucleic acid present in ALL of?
Viruses
What is ATP required for in terms of muscles?
Contractions
What is required for muscle contraction?
ATP
Difference between transverse and longitudinal sections
Longitudinal
-cells have been cut vertically down
-rectangular cells
Transverse
-cells are rounder
Draw, label and describe all of the organelles involved in the synthesis of proteins
(Check notes)
Endosymbiont advantages to chloroplasts and mitochondria
Evolutionary advantage
Compartmentalisation
Protection of mitochondria and chloroplasts
Raw materials supplied to organelles
Internalised energy source and nutrient supply
Endosymbiosis
Entered via endocytosis in order to interact for the advantages of each other
Do virus particles have chromosomes?
No
Similarities between eukaryotic and prokaryotic cells
Both contain…
Ribosomes
Cell membranes
DNA
Genetic material
Main difference between simple and stratified epithelial tissue
Simple = 1 layer of cells
Stratified = more cell layers
What do mitochondria do during respiration?
Release heat
How might the Cristae of mitochondria be part of the endosymbiont hypothesis?
May be involved in cellular respiration like the mesosome of prokaryotes
How many tissue types in an organ?
Several
How are secretory vesicles produces and how are digestive enzymes secreted from a cell?
Golgi body packages enzymes into vesicles
Vesicles move to cell surface membrane
Vesicles fuse with membrane
Exocytosis
What type of cells have its DNA associated with histones? Prokaryotic and Eukaryotic cells?
Eukaryotic cells
Why can’t virus particles synthesise proteins?
No ribosomes
No ATP
