u1: eukaryotic organisms Flashcards
what cell organelle is also present in bacteria
ribosomes
what do many cell organelles have
a double membrane
what do ribosomes not have
a double membrane
nucleus
why is it important
- stores and transmits genetic information
- stored DNA is used to synthesize proteins
- DNA molecules are wrapped in proteins to form chromosomes
- in non-dividing cells: DNA is in form of chromatin (less compact than chromosomes)
what else does the nucleus contain?
- nucleolus
- nucleoplasm
- nuclear matrix
- nuclear pore complex
what is the nucleus covered with?
- double membrane: inner and outer
- nuclear envelope/membrane has nuclear pore complex
nucleolus
site of ribosome production
nucleoplasm
nuclear fluid (like cytoplasm)
nuclear matrix
proteins tht give nucleus support and structure
nuclear pore complex
pores in nuclear membrane/envelope that allow small molecules to enter/exit nucleus
where is chromatin located in the nucleus
floating within the nucleoplasm
endoplasmic reticulum
- connected to nuclear envelope
- rough ER: studded with ribosomes to make proteins
- smooth ER: no ribosomes, makes lipids
what lipids does the smooth ER make?
- phospholipids
- estrogen
- testosterone
what do ribosomes do? whys it important?
- make proteins using the genetic material in nucleus
- proteins have many functions like expressing genetic traits
golgi apparatus
- proteins go to golgi apparatus from rough ER
- each golgi compartment modifies the proteins
- the modified proteins have different locations
where do proteins go after the golgi apparatus? how r they delivered?
- cell organelles
- cell membrane (to go outside the cell)
- delivered by vesicles
vesicles
- small, round, sac-like structures
- double-membraned
- smaller than endoplasmic reticulum
- some vesicles transport things inside, some transport outside
examples of vesicles
vacuoles and lysosomes
what organelles transport and process proteins in the cell? what is the process called?
- endomembrane transport
- nuclear envelope, ER, golgi apparatus, nd vesicles
how does endomembrane transport occur?
- rough ER makes proteins. these proteins dont freefloat in cytoplasm, instead they stay in the leumen
- proteins go to golgi by a vesicle. vesicle merges with golgi. golgi processes protein. i.e. it can add sugar and mae it a signalling molecule
- products go through golgi and exit in vesicles to: leave cell, be placed in cell membrane, or go to another destination
lysosomes
- “cellular stomachs”
- spherical organelles
- have acidic fluid and digestive enzymes
- digests: ingested products, worn out organelles, bacteria, etc
chloroplasts
- contain chlorophyll
- complex internal structure
- liquid stroma
- flattened discs called thylakoids
- stack of thylakoids is called granum/grana
thylakoids
contain chlorophyll
chlorophyll
how does it do wht it does
- photosynthetic pigment
- converts light energy/water/carbon dioxide into sugar through redox reactions
what do chloroplasts have in common with mitochondria
both have a double membrane
mitochondria
- break down high energy organic molecules (like glucose) into useable energy (ATP)
- inner membrane is called cristae
- fluid filled space in inner membrane is called “mitochondrial matrix”
define cytoskeleton
internal network of protein fibres inside of all cells
purpose of cytoskeleton
protein fibres extend throughout cytoplasm to:
1. provide structure
2. anchor cell membrane/other organelles in place
examples of protein fibres
- microtubules
- intermediate filaments
- microfilaments
how do the protein fibres help with endomembrane transport?
by ensuring all organelles stay in place, proteins can be transported effectively
microtubules
- maintain cell shape
- used in cell division (spindle fibers)
- thickest/biggest
intermediate filaments
- maintain cell shape
- anchor organelles
- medium shape
microfilaments
- maintain cell shape
- help cell cleave during division
- thinnest
what are protein fibres also called
structural proteins
diff btwn chloroplasts and mitochondria
- chloroplasts do photosynthesis
- mitochondria does cellular respiration
