Cell Structure Flashcards
What type of cells have cell wall
Prokaryotes and plant cells
What is the difference between the cell wall in prokaryotes and plant cells?
Plants cell wall is made out of cellulose.
Prokaryotic cell wall is made out of peptidoglycans.
What is cellulose
A secretion from the cell that forms a layer on the cell and makes the cell wall
What are peptidoglycans
Proteins carbohydrates and sugars
Difference between plant and animal cells?
Plant cells have one large vacuole….. Animal cells have many small vacuoles
Plant cells have chloroplast… Animal cells don’t
Plant cells have their nucleus to one side of the cell…… Animal cells have their nucleus in the centre
Plant cells do not have centrioles or centrosome…. Animals have centrioles and centrosome
Plant cells have plastids…… Animal cells lack plastids
Plant cells have cell wall……. Animal cells only have cell membrane.
Plant cells are larger and rectangular in shape…… Animal cells are smaller than plant cells
Plant cells store glucose as starch…… Animal cells store glucose as glycogen
Characteristics of chloroplasts
- contain chlorophyll
- have their own DNA and ribosomes (systhesise protein)
- double membranes
Function of chloroplasts
To generate food and store it as ATP for the plant with the process of photosynthesis
Where are chloroplasts found and in what type of cells?
Chloroplasts are found in plant cells and algae
They are usually found in parts that receive sunlight.
What is the function of cell wall
Provide strength and rigidity to the cell and protects it
Characteristics of cell wall
Made from cellulose (made with peptidoglycans in prokaryotes)
Permeable and allows all things to pass through
Very strong layer
Characteristics of microvilli
Finger like projections
They are stationary and do not contribute to movement
Function of microvilli
To increase surface area and absorption rate so the cell can get it’s nutrients
Where are microvilli found?
Epithelial tissue in trachea and internal layer of intestines
Characteristics of cilia
- hair like structures on the cell
- they whip around and provide movement
- they are considered as separate organell
- microtubules in the cilia helps in movement of cilia
-have membrane
Function of cilia
Help in movement of the cell in fluid spaces and also to push away foreign particles
Where are cilia found
Cila are found in epithelial cells of trachea
Also found in fallopian tube of female reproductive system
Flagella characteristics
- Is a thin stretched out thread like structure
- is usually part of the external structure of the cell
- is membranous
- whips and moves to provide movement
- made out of proteins and microfilaments
Where is a flagella found
Usually on single celled organisms or on human sperm cell
What are lysosomes
They are vesicles that contain hydrolytic enzyme mixture
Membrane bound
Function of lysosomes?
Help in digestion and processing food
Help in the breakdown of foreign bodies
Decomposes old organelles
What is a vesicle
Membrane bound sac-like structure that is usually involved in storage, transport or secretion and excretion in a cell.
They usually contain fluid that determines their purpose
What is the golgi apparatus?
It is a series of membranous sac-like structures that are flattened out.
The sacs can be called cisternae and contain lumen in them.
Products are stored in the cisternae, processed and transported out through transport vesicles
Cisternae is found in
Golgi apparatus and endoplasmic reticulum
Types of endoplasmic reticulum and their difference (talk about their function)
Rough endoplasmic reticulum and smooth endoplasmic reticulum
Rough has ribosomes and is involved in protein synthesis
Smooth doesn’t have ribosomes and is involved in the production of enzymes and lipids (helps in metabolism of carbohydrates)
Common characteristics of the two types of endoplasmic reticulum
Both are a structure of flattened out membranous vesicles
Linked to the nucleus
Vacuoles characteristics , function and location
- membrane bound organells
- involves in the storage of
___water
___waste materials (isolates waste materials)
___sugar in form of disaccharide sucrose
___nutriets
___food molecules
___salts - contractile vacuoles help in Removing excess water out of cells and are found in paramecium
Vacuoles are found in animal cells as many small organelles and found in plant cells and one large organelle
Write the equation for process of glucose to ATP
C6H12O6 + 6O2 —— 6CO2 + 6H20 + ATP
Full form of ATP
Adenosine triphosphate
Mitochondria characteristics
- double membranes
- inner membrane has folds called cristae
- outer membrane is semi permeable
- it divides by binary fission
- originally a prokaryote before entering into an endosymbiotic relationship with a larger eukaryotic cell
- have own dna
Function of mitochondria
- site of cellular respiration
- provides energy for the cell
- generation of ATP
___________ cells have inter membrane space between their two memebranes
Mitochondria
Nucleolus characteristics and functions
An internal sphere in the nucleus
Site of ribosome production (ribosome biogenesis)
Not membranous
Accumulation of large amounts of RNA and proteins
Cells may have more than one nucleous
What is DNA
Deoxyribonucleic acid
What is RNA
Ribonucleic acid
What is ribosome biogenesis
Systhesis of ribosomes
(Nucleolus)
What is the nucleus
Contains/ holds DNA
Controls the synthesis of proteins
Is membranous (bilipid layer)
Separate chromosomes from other cell components
Purpose of nuclear pores
Nuclear pores allow interchange of substances
Endoplasmic reticulum is also connected to nuclear pores
Some immune cells have ___________________ nucleus meaning_____________________
Multi-lobed …… The nucleus is separated into multiple spheres along with the genes
What are ribosomes
Responsible for protein synthesis
Could be found freely suspended in cytoplasm
Also found on rough endoplasmic reticulum
Difference between ribosomes in prokaryotes and eukaryotes
Prokaryotes: 70s (small subunits = 30s and large subunits = 50s)
Eukaryotes: 80s (small subunits = 40s and large subunits = 60s)
Cytoplasm of the cell
- dense fluid like substance
- has organelles contained within it
- water based with proteins
- has dissolved minerals and proteins freely suspended
What is cystol
It is the fluid part of cytoplasm excluding the mineral deposits
_____________ is the layer dividing the cell from other cells. Describe it
Plasma membrane / cell membrane. Is a semi permeable layer that separates internal components from external components and allows only selective substances to pass through.
Describe eukaryotes
Complex cells
Defined nucleus
Have many membrane bound organelles
Unicellular and multicellular
Membrane bound compartments advantages
Separation of function into individual units
Storage of molecules
Protection from chemicals
Prokaryotic cells characteristics
No defined nucleus
Unicellular organisms
Consists of group bacteria and archaebacteria.
Simple cells (than eukaryotic)
Smaller than eukaryotic cells
What are the Three domains of life?
There are three domains:
- bacteria
- Archaea (archaebacteria / extremophiles)
- eukarya
Bacteria and archea are unicellular organism and are prokaryotic cells
Archea are called extremophiles as they can exist is rough conditions
Outline the external features of prokaryotic cells
Cell Membrane
Cell wall
Pili
Flagella
Slime capsule
What is the smile capsule?
This polysaccharide layer (carbohydrate layer) which protects against desiccation and phagocytosis (being engulfed)
What is polysacchride
Carbohydrate layer
What is phagocytosis
Being engulfed by another cell
What is the pili?
They are hair like structures on the surface of prokaryotic cells
Their function is to enable adherence and mediate bacterial conjugation
What is bacterial conjugation
Exchange or transport of genetic material through cell-cell contact.
This happens when a bridge like connection is formed with the pili of the cells in reference.
What is the nucleoid
It is the centre of the cell that has DNA and chromosomes
Not membrane bound
What are plasmids
They are circular structures/molecules of DNA that can be transferred between bacteria through horizontal gene transfer or bacterial conjugation
Difference between gram positive and gram negative
Gram positive: thick layer or peptidoglycans
Appear pink in microscope
Gram negative: thin layer of peptidoglycans
Appear purple in microscope
Layer of lipopolysaccharides and proteins and an additional cell membrane
What are lipopolysacchrides
Composed of a lipids and a polysaccharide
What are lipids
Organic compounds
Fatty acids
Insoluble in water
What is binary fission
The process in which bacteria divide in a really fast pace
- DNA replicates
- 2 DNA loops attach to the membrane
- membrane elongates and pinches off
It is where the cell copies and divides
