Cell Structure and Organisation Flashcards
Mitochondria labels
- stalked particles
- cristae
- matrix (where aerobic respiration takes place)
- intermembrane space
- outer membrane
- inner membrane
- small circle of DNA
- ribosomes
Mitochondria structure
- cylindrical
- bound by double membrane
- folded inner membrane (cristae)
- fluid fills intermembrane space
- synthesises own proteins and self replicates using proteins, lipids, circle of DNA and ribosomes
Function of mitochondrion
Synthesise ATP by aerobic respiration
Where can many mitochondria be found?
Liver and muscle cells
Nucleus labels
- nuclear pore
- nuclear envelope
- nucleolus
- chromatin
- outer membrane
- inner membrane
- ribosomes
Nucleus structure
- spherical
- bound by double membrane
- contains chromatin + nucleolus
Function of nucleus
Site of DNA replication and transcription
Function of chromatin
DNA condenses to form chromosomes for cell division
Function of nucleolus
Site of rRNA synthesis and ribosome assembly
Function of nuclear pores
Gaps in envelope allow passage of large molecules in and out (mRNA + ribosomes)
Function of nuclear envelope
Separates nucleus from cytoplasm
Ribosome labels
- large subunit
- protein chain
- amino acid
- mRNA
- small subunit
Ribosome structure
- 1 large subunit + 1 small subunit
- consists of rRNA + protein - either attached to RER or free in cytoplasm
Function of ribosomes
Protein synthesis, protein assembly, translation (mRNA assembles proteins from amino acids)
Rough endoplasmic reticulum labels
- ribosomes
- cisternae
Rough endoplasmic reticulum structure
-flattened sacs (cisternae) with ribosomes attached
Function of rough endoplasmic reticulum
Protein transport (proteins made by ribosomes attached), packages proteins into vesicles to travel to Golgi body
Smooth endoplasmic reticulum labels
-cisternae
Smooth endoplasmic reticulum structure
-flattened sacs (cisternae), no ribosomes attached
Function of smooth endoplasmic reticulum
Synthesis and transport of lipids
Golgi body labels
- cisternae
- vesicles from RER
- vesicles from Golgi
Golgi body structure
-series of dynamic flattened sacs and vesicles
Function of Golgi body
Modification of proteins from RER, packages proteins into vesicles transported elsewhere, also forms lysosomes
Lysosome labels
- single wall membrane
- enzyme complexes
Lysosome structure
- vacuoles that contain digesting enzymes
- bound by single membrane
Function of lysosomes
Digest solid material/’worn out’ organelles by phagocytosis
Centriole labels
- spindle
- triplet microtubules
Centriole structure
-made of tubulin (protein)
Function of centrioles
Organise microtubules that make spindle in cell division
Plasmodesmata structure
-strands of cytoplasm that pass through pits in cell wall to neighbouring cells
Function of plasmodesmata
Transport water along symplast pathway through root
Chloroplast labels
- outer membrane
- inner membrane
- stroma
- lipid droplet
- granum (stack of thylakoids)
- intergranal lamella (thylakoid)
- ring of DNA
- starch granule
- ribosomes
Chloroplast structure
- surrounded by double membrane
- liquid stroma contains starch grains, lipid droplets, DNA and ribosomes
- flattened sacs = thylakoids
- granum contains chlorophyll
Function of chloroplasts
Absorb light energy for photosynthesis
Vacuole labels
-tonoplast
Vacuole structure
- large permanent fluid filled sac
- single membrane (tonoplast)
Function of vacuoles
Storage site of chemicals (e.g glucose), osmotic system which supports plant tissues
Prokaryotic bacterium structure
- nucleoid DNA
- ribosomes
- flagellum
- capsule
- cell membrane
- mesosome
- murein cell wall
Virus structure
- protein coat
- nucleic acid
- DNA/RNA/a few genes
Cell theory
All living organisms made of cells (multicellular or unicellular)
Cells are the basic units of life
Cells arise from pre-existing cells
Prokaryotes
- bacteria, blue-green algae
- DNA free in cytoplasm
- murein cell wall
- small ribosomes
- no nuclear membrane
- no membrane bound organelles
- plasmids
Eukaryotes
- plants, animals, fungi, protoctists
- DNA located in chromosomes
- cellulose cell wall
- large ribosomes
- distinct membrane bound nucleus
- membrane bound organelles
- no plasmids
Tissue definition + examples
Aggregation (group) of cells with same structure and function working together
E.g. Epithelial, muscle, connective
Organ definition + examples
Aggregation of different tissues working together to carry out function for organism
E.g. Brain, liver, heart
Organ system definition + examples
Group of organs working together with a particular role
E.g. Digestive system, reproductive system, respiratory system, cardiovascular system
Epithelial
- forms a continuous layer and covers internal & external surfaces of body
- cells sit on a basement membrane
3 types of epithelial tissue
- cuboidal epithelium
- columnar epithelium
- squamous epithelium
Cuboidal epithelium
- cube shaped
- found in kidney nephron (in PCT) & salivary gland ducts
Columnar epithelium
- elongated cells
- cilia if lining tube where substances like mucus/eggs move through
Squamous epithelium
- flattened cells
- form walls of alveolus in lungs & line Bowman’s (renal) capsule of kidney nephron
3 types of muscle tissue
- skeletal/striated
- smooth
- cardiac
Skeletal
- voluntary control
- tires easily
- striated appearance from protein fibrils within fused muscle cells
Smooth
- contract involuntarily
- form walls of hollow organs (e.g stomach)
Cardiac
- contract rhythmically
- never tire
- only found in heart
Connective tissue
- binds and supports tissues
- consists of cells, elastic & collagen fibres in an extracellular matrix (proteins and polysaccharides secreted by neighbouring tissues)
