Cell Biology part 1 Flashcards
What are the non living levels of organisation?
1 Atom
2 Molecule
3 Organelles
4 Viruses
What are the living levels of organisation?
1 Cell 2 Tissue 3 Organ 4 Organ systems 5 Organism
What did Robert Hooke do in 1665?
He used a microscope to look at a slice of cork. (dead plant cell walls)
- He saw was small boxes
What did Anton van Leeuwenhoek do in 1674?
He was first to view a living thing. Using a handheld microscope to look at pond water and teeth scrapings.
What did Matthias Schleiden conclude in 1838?
That all plants were made of cells.
What did Theodore Schwann conclude in 1839?
That all animals were made of cells.
Who are the cofounders of the cell theory?
Schleiden and Schwann
Who discovered cell division in 1855?
Rudolph Virchow
Name the three principles of cell theory
- all living things are made of cells
- cells are the basic unit of life
- cells come from reproduction of existing cells
Name the 3 microscopy techniques
Optical/light
Scanning probe
Electron
Briefly describe how optical microscopy works
light is passed through a specimen and focused via a glass lense.
Briefly describe how electron microscopy works
electrons passed through a dead specimen focused by a magnetic lense.
What is confocal microscopy?
A type of optical microscopy using a laser beam across a transparent specimen.
- allows 3D image on computer
What is magnification?
the increase in object size.
What is resolution?
how well two close objects are shown as separate.
What are the sizes of cells?
range from 1 mm to 1 micrometre
What makes a prokaryotic cell differ from eukaryotic?
They don’t have a nucleus and have much smaller and simpler structures.
Name the two domains for prokaryotic cells
- Bacteria
- Archaea
What is the width and length of bacteria?
around 1 - 1.5 micrometres wide and 2 - 6 micrometres long
What are the 3 basic shapes of bacteria?
- Spherical coccus
- Rod - shaped bacillus
- spiral sprillum (if rigid) or spirochete (if flexible)
What is in bacterias cell envelope?
Plasma membrane Cell wall Glycocalyx Flagella Ribsomes Nucleoid
What is bacterias plasma membrane for?
- has lipid bilayer with imbedded and peripheral protein
- forms mesosomes (internal pouches)
What is the function of cell wall of bacteria?
maintain cell shape.
Bonus: strengthened by peptidoglycan
What is glycocalyx in bacteria?
layer of polysaccharides outside of the cell wall.
What is the flagella?
Taillike structure for movement
What are ribosomes for in bacteria?
used for translation from RNA to protein.
What is the function of the nucleoid in bacteria?
Holds genetic material in a circular structure.
Name the 4 domain Eukarya
- protists
- fungi
- plants
- animals
Name components of eukaryotic cells.
- Nucleus
- special organelles
- plasma membrane
- (for plant cells and some others, cell wall)
Name the two organelle classes and what they do
Endomembrane system - communicate with each other via vesicles and channels
Energy-related - independent
What are the key features of our cell membrane?
Has phospholipid bilayer with protein as channels ,markers and receptors.
- also has cholesterol for rigidity.
What are the key nucleus features?
sphere that has another sphere called nucleolus.
stored DNA &manages cell function
Describe the plant cell wall
rigid, made of cellulose, carbs and protein. its a boundary around plant cell membrane providing structure and support.
What is cytoplasm and its function?
fluid inside cell membrane containing salts, minerals and organic molecules.
surrounds organelles.
What is the Cytoskeleton?
thin fibrous elements made of microtubules (hollow tubes) and microfilaments (threads made out of actin).
What is the Cytoskeletons function?
acts as support for organelles and maintains cells shape.
What are ribosomes structure and function?
made up of 2 subunits made of protein and RNA.
location of protein synthesis.
Describe what the Endoplasmic Reticulum is.
a system of membranous tubules and sacs. and a pathway for molecules to move from one part of the cell to another.
What are the two types of ER and the main difference?
Smooth (not covered in ribosomes) and rough (covered in ribosomes)
Describe the function of the rough ER
It has cells that make lots of protein to be taken from the cell or put into the cell membrane.
Describe the function of the smooth ER
It involved in the synthesis of lipids and breakdown of toxic substances.
What is the structure and function of Golgi apparatus?
stacked flat sacs that receive protein from the rER and send them to other organelles or out of the cell
What is the structure and function of mitochondria?
- folded membrane (folds are cristae) in an outer membrane.
- converts energy in food for work (cellular respiration)
Describe lysosomes
spherical organelles that have hydrolytic enzymes within single membranes
What is the function of lyosomes?
break down food particles, invading objects or worn out cell bits.
What is the structure and function of peroxisomes?
spherical with enzymes in single membranes.
- break down hydrogen peroxide, a toxic substance that can be produced in metabolism
What are cilia and flagella?
Hair like organelles (made of 10 pairs of macro-tubules) that extend from cell surface. cilia(in large numbers) flagella (in less numbers and longer)
Describe centrioles
9 set of 3 microtubules in a ring. - exist in pairs. play big role in mitosis.
There are 3 plastids in plant cells, name them.
chloroplasts
chromoplasts
leucoplasts
Describe the structure-function of chloroplasts
stacked sacs (thylakoids) with chlorophyll. surrounded by a double membrane. - for photosynthesis
Function of chromoplasts
make and store pigment
Function of leucoplasts
store food like protein, carbs and starch
Name the differences of plant and animal cells.
- animals have no chloroplast
- animals have no cell wall
- Vacuoles in plants are much bigger than in animals
What is interphase and what does it consist?
Growth that occurs between cell divisions(cells spend most life here). consists of G1,S, and G2
What is M phase?
after G2, when the cell divides in 2 phases mitosis and cytokinesis
What is mitosis?
division of the cell nucleus
What is cytokinesis?
Division of cytoplasm
What happens in G1,S THEN G2?
G1 - cell growth
S - DNA replication
G2 - prep for mitosis
How do prokaryotes divide?
via binary fission, a regular pattern of growth, DNA replication and cell division.
What are the 3 basic categories of cell differentiation?
- GERM CELLS
- SOMATIC CELLS
- STEM CELLS
What are stem cells and their properties?
unspecialised or partially specialised cells.
- self renewing
- potent
What are the classifications for stem cells?
Embryonic
Adult
