1 | Cells Flashcards
2 types of microscopes?
- light microscope
- electron microscope
Structural features of a nucleus?
Dense matter surrounded by a membrane
- contains DNA/chromatin/chromosomes
Function of a nucleus
Controls cell activities
- cell growth
- repair of worn out parts
Structural features of cytoplasm
Jelly-like substance in the intercellular space
Function of cytoplasm?
Site of cellular activities
Structural features of rough endoplasmic reticulum (RER)
- Surface appears rough
- Network of flattened spaces studded with ribosomes
- Continuous with nuclear envelope
Function of the RER
transport proteins made by ribosomes to GG for secretion out of the cell
What is the RER?
rough endoplasmic reticulum
What is the SER?
smooth endoplasmic reticulum
Structural features SER?
- no ribosomes
- more tubular
Function of the SER?
- synthesizes fats and steroids
- involved in detoxification of harmful substances
Function of the ribosome?
- synthesise proteins
- ribosomes on RER synthesise protein for secretion
- free ribosomes in cytoplasm synthesise protein for use within the cell
Structural features of cellulose cell wall?
- rigid
- fully permeable
Function of cellulose cell wall?
- protect cell from injury
- provides fixed shape
What is the GG?
Golgi apparatus / Golgi body
Structural features of the GG?
stack of flattened discs
Function of the GG?
- stores and modifies proteins from the ER
- packages substances in vesicles for secretion out of the cell
Structural features of the mitochondria?
oval in shape
Function of the mitochondria?
The site where energy is released during aerobic respiration
- glucose is oxidised
Energy used for cellular activities like growth and respiration
Structural features of chloroplasts
contains chlorophyll
Function of chloroplasts
site of photosynthesis
Structural features of cell surface membrane
selectively permeable
Functions of cell surface membranes
Controls movement of substances in and out of the cell
Structural features of vacuoles
Plant: large, central vacuole
Animal: small, numerous vacuoles
Function of vacuoles
stores water and food minerals
- carbohydrates and vitamins
Difference between plant and animal cells
notes
3 specialised cells
RBC
Xylem cell
Root hair cell
Structural adaptations and function of RBC
contains haemoglobin
- haemoglobin binds reversibly to oxygen
circular biconcave shape
- increases surface area to volume ratio for faster uptake of O2
absence of nucleus
- allows packing of more haemoglobin
Structural adaptations and function of xylem cell
only contains cell wall; absence of cytoplasm (hollow and narrow)
- water and absorbed mineral salts are carried up in a continuous stream easily
ligin deposited on walls
-
Structural adaptations and function of xylem cell
only contains cell wall; absence of cytoplasm (hollow and narrow)
- water and absorbed mineral salts are carried up in a continuous stream easily
lignin deposited on walls
- provides structural support
Structural adaptations and function of root hair cell
long and narrow extension
- increases surface area 2 volume ratio for faster absorption of water and mineral salts
lower water potential in vacuole
- water enters the root hair cell via osmosis
contain numerous mitochondria
- release energy for active transport of mineral salts
Levels of organisation in living things
Cells → simple tissues → complex tissues → organs → organ system → organism
What are simple tissues?
contain cells of the same type which are grouped together to carry out a specialised function
What are complex tissues?
contain cells of the different types which are grouped together to carry out specialised function
What is an organ?
made up of tissues that are assembled together to perform one specialised function
What is an organ system
formed from several different organs, whose functions are closely related.
