Chapter 2 - Basic components of living systems - cell types Flashcards
name the two cell types
eukaryotic and prokaryotic
where do reactions in a cell take place
the cytoplasm
why are membranes selectively permeable
to control what substances can enter or exit the cell or organelle
name ten organelles in a eukaryotic cell (there are 14)
nucleus nucleolus smooth endoplasmic reticulum rough endoplasmic reticulum Golgi apparatus microtubule network mitochondria vesicles ribosomes cell-surface membrane cytosol centriole cytoskeleton secretory vesicles
what does the nucleus contain
DNA/genetic material
what is the double membrane containing the DNA called
the nuclear envelope
where does RNA get out of the nuclear envelope
through the nuclear pores (too small for DNA)
DNA associates with ________ to form a complex called _______ which coils and condenses to form _________
histones to form chromatin…to form chromosomes
what is the nucleolus
an area within the nucleus responsible for producing ribosomes
what are mitochondria
the site of the final stages of respiration
what would a very active cell have a large number of
mitochondria
what is (mt)DNA
mitochondrial DNA
what are the matrix and the cristae
the inner membrane of the mitochondria is folded to form cristae and the fluid area inside the mitochondria is the matrix
what are vesicles
membranous sacs containing fluid for transport of substances inside the cell
what are lysosomes
specialised vesicles containing hydrolytic enzymes for breaking down waste. they play an important role in apoptosis (programmed cell death) and the immune system
what is the cytoskeleton
present throughout the cytoplasm, it is a network of fibres necessary for the shape and stability of the cell
what are the three components of the cytoskeleton
microfilaments - contractile filaments
microtubules - scaffold
intermediate fibres - mechanical strength
what are centrioles
a component of the cytoskeleton. two associated centrioles form a centrosome involved in cell division
what are flagella and what are they used for
whip-like extensions that protrude from cells to enable mobility
what are cilia and what are they used for
hair-like extensions that protrude from cells for either a sensory purpose (eg. in the nose) or to beat and move substances (eg. mucus in the airways)
how are microtubules arranged in cilia
9+2 - two central microtubules surrounded by nine pairs of microtubules
what are the three main organelles involved in protein synthesis
Golgi apparatus, ribosomes, endoplasmic reticulum
what is the endoplasmic reticulum
a network of membranes enclosing flattened sacs called cisternae
what are the differences between the smooth and the rough endoplasmic reticulum
smooth - responsible for carbohydrate and lipid synthesis, and storage
rough - has ribosomes bound to the surface and is responsible for protein synthesis
where are ribosomes found
free floating in the cytoplasm or bound to endoplasmic reticulum
what are ribosomes made of
RNA molecules (they are not surrounded by a membrane)
what is the Golgi apparatus
similar to the smooth endoplasmic reticulum - a compact structure made of cisternae - it packages proteins into vesicles
describe the process of protein production
they are synthesised in the ribosomes on the rough endoplasmic reticulum. they then pass to the cisternae to be packaged into transport vesicles. the vesicles move to the Golgi apparatus via the cytoskeleton. the vesicles fuse with the cis face of the Golgi apparatus and the proteins enter. the proteins are structurally modified before leaving the Golgi apparatus in vesicles from its trans face. secretory vesicles carry proteins toward the cell surface membrane and release their contents via exocytosis
what are cell walls made of
cellulose - a complex carbohydrate
what is the purpose of the cell wall
rigidity and defence
what are the main three unique features of plant cells
cell walls, chloroplasts and vacuoles
what are vacuoles
membrane lined sacs containing sap important in maintaining turgor
what is the selectively permeable membrane of a vacuole called
tonoplast
what are chloroplasts
the organelles responsible for photosynthesis
name the parts of the chloroplasts
stroma - the fluid
thylakoids - flattened sacs
granum - stack of thylakoids
lamellae - membranes joining granum
what are the two domains of single-celled organisms
archaea and bacteria
describe the DNA of prokaryotes
not in a nucleus, generally only one supercoiled chromosome
what is the difference between eukaryotic and prokaryotic ribosomes
prokaryotic ribosomes are smaller
what is the prokaryotic cell wall made of
peptidoglycan/murein
what are the differences between eukaryotic and prokaryotic flagellum
the prokaryotic flagella is thinner and doesn’t have the 9+2 structure. the flagellum is attached to the cell membrane by a basal body and rotated by a molecular motor
