Chapter 1:cell Strructure And Microscopes Flashcards
State 5 differences between eukaryotic and prokaryotic cells
-euk, have a nucleus containing their genetic dna, so have membrane bound organelles,
-pro, have genetic dna free floating in cytoplasm bc no nucleus,so no membrane bound organelles
-eukaryotic, have 80s ribosomes, 25nm
-Pro, have 70s ribosomes, 18nm
-euk,have dna that is linear and associated with histones
-pro, have dna that is circular and not associated with histones
-euk are much larger 100 micromètres
Pro are much smaller, 1-5 micromètres
-in euk, plant cell walls made of cellulose and fungi cell walls made of lignin
-in pro, cell walls made of peptidoglycan (polysaccharide and amino acids) and murein
State 3 similarities between eukaryotic and prokaryotic organisms
-both have dna
-both have cytoplasm
-both hve cell membranes
Describe the steps involved in the production and secretion of proteins (with the cell structures involved)
-translation (protein synthesis) occurs at the ribosomes so a protein is produced
-RER processes proteins made by the ribosomes
-transport vesicles transport these proteins made to the golgi vesicle
-golgi vesicle modifies(eg folding into a polypeptide chain) and packages proteins (eg packaging into secretory vesicles)
-secretory vesicle fuses with cell surface membrane and contents are released through the process of exocytosis
Give the function and describe the structure of the golgi vesicle
-function is to modify (eg fold into polypeptide chains) and package proteins and lipids into secretory vesicles
-contents can then be transported to other destinations in the cell eg to produce lysosomes
-fluid filled flattened sacs
-have a layered appearance, so membranes are not continuous and form separate compartments
-are not connected to the nuclear envelope
-bound by a single membrane
Give the function and describe the structure of the rough endoplamsic reticulum
Function is to process proteins made by ribosomes
-flattened sacs
-with continuous folds
-connected to the nuclear envelope
-with 80s ribsoomes on the surface
Give the function of lysozomes
-specialist forms of vesicles which contain hydrolyctic enzymes which break down waste materials such as warn out organelles in an acidic environment
Function of the nucleus
-site of dna replication, so contains the genetic code for each cell
-and site of transcription, so produces mRNA
(Attached to the ER)
What type of membrane is the nuclear membrane in animal cells
-a double membrane
Nuclear pore function
Allows substances such as ribosomes and mRNA to leave the nucleus
And substances such as enzymes like dna polymerase and signaling molecules to travel in
Nucleolus function and structure
-site of ribosome production
-densest region
-contains proteins and rna on it
Chromatin function
Materials from which chromosomes are made from ( so a tightly coiled combination of dna and histone proteins)
State the four parts of the nucleus
Nuclear envelope- double membrane
Nucleolus
Chromatin
Nuclear pore
Microvilli function in an animal cell
Increase the surface area for absorption and diffusion
And so mainly found in the small intestine to maximize nutrient absorption
Cilia function and structure in animal cells
-Hair like structures composed of microtubules in a 9+2 formation
-function is to move substances across the surface of a cell
Smooth endoplasmic reticulum function and structure
Function, is that it processes and produces lipids, carbohydrates and steroids
-system of membrane bound sacs
Centrosome function and structure
-the main microtubule organizing center, involved in cell division when centrioles produce spindle fibres
-consists of two centrioles at right angles t each other and close to the nucleus
Centriole function and structure
-produce spindle fibres during mitosis
-one of 2 hollow cylindrical structures made up of microtubules
Microtubules radiating from the centrosome in an animal cell, function and structure
-form the cytoskeleton of the cell, so provide support and movement to the cell
-made of of alpha and beta tubulin which form dimers
-dimers form microfilaments
-13 micro filaments form a microtubule
Mitochondria function and structure explanation
Function is to carry out aerobic respiration, to produce atp to provide energy
-contain a double membrane
-inner membrane is folded to form projections called Christae, which contain enzymes and give a large surface area
-cristae project inwards into the matrix, which contains enzymes for aerobic respiration
-contain circular dna and 70s ribosomes
Chloroplast function, structure and features explain
-function is that they are the site of photosynthesis
-contain many thin thylakoid membranes(folded membranes) which are stacked together to form grana (granular is singular)
-grana linked together by lamella, which are thin and flat thylakoid membranes
(These maximize the surface area being exposed to light)
-contains a starch granule for storage
-contain chlorophyll, which are photosynthetic pigments
-contain circular dna and 70s ribosomes, to synthesize proteins for chloroplast replication and for photysyntheis
-are filled with a fluid called stroma which contains enzymes for photosynthesis
Which organisms are centorosmes found in and which organisms are they not found in
-found in animals
-not found in plants, fungi or prokaryotes
Plasmodesmata function
Channels that pass through the cell walls of adjoining plant cells, which allow for communication between cells
State the names of the two parts of the vacuole and describe their function.
Tonoplast, the partially permeable cell membrane of thr vacuole
Cell sap, consist of minerals, salts, sugars, amino acids waste substances and pigments
