Cell Structure Flashcards
Is a prokaryotic cell bigger or smaller than an eukaryotic cell
Smaller
What doesn’t a prokaryotic cell have
Nucleus, nuclear envelope, no membrane bound organelles
What are the membrane bound organelles
Nucleus, Golgi apparatus, endoplasmic reticulum, lysosomes, mitochondria, chloroplasts
How are prokaryotic cells adapted to survive in every habitat
They’re adaptable and versatile
What do prokaryotic cells store food reserves as
Glycogen and oil droplets
What size ribosomes do prokaryotic cells have
70s
What are in prokaryotic cells
All: 70s ribosomes, cytoplasm, circular dna, cell membrane, cell wall
Some: slime capsule, flagella, plasmids
What’s the difference between circular dna and plasmids
Circular dna is free in cytoplasm and possesses the generic info for replication of bacterial cells. Plasmids are separate from circular dna and are smaller pieces of dna that reproduce independently, they possess genes that may aid in survival of bacteria in adverse conditions and can be used as vectors between bacteria.
What is the function of a cell membrane in a prokaryotic cell
Controls entry and exit of cell, permeable layer
What is a cell wall ( prokaryotic cell)
Made up of murein (glycoprotein). For strength and structure, protect against damage, physical barrier
What is a slime capsule
Layer of slime around the cell, protects bacterium from other cells helps groups of bacteria stuck together for more protection
What organelles are is an animal eukaryote
Nucleolus, nucleus, nuclear envelope, nuclear pores, nucleoplasm, mitochondrion, rough endoplasmic reticulum, smooth endoplasmic reticulum, 80s ribosomes, Golgi apparatus, lysosomes
What is the ultra structure
The internal structure of cells
What does the nucleus do
Control centre of cell through nRNA and tRNA ( protein synthesis), manufacture rna
What is the nuclear envelope
Double membrane surrounding nucleus, controls entry and exit of materials
What are nuclear pores
The gaps that allow passage of large molecules E.g messenger RNA out of nucleus
What is the nucleoplasm
Granular, jelly like material that makes up the bulk of the nucleus
What is the nucleolus
Small spherical region within nucleoplasm, may be more than one in nucleus, manufacture ribosomal RNA and assembles ribosmones
What is chromotin
The material that makes up the chromosomes
What is function of mitochondrion
Aerobic respiration, produce energy carrier molecule ATP
What is the function of the double membrane in a mitochondria
Control entry and exit of material, inner membrane is folded to form extensions called cristae
What is the function of cristae
Provide large surface area for attachment of enzymes/ other proteins required in respiration.
What is the matrix in a mitrochondrion
Constrains proteins, lipids, ribosomes and dna. Controls production of some mitochondria proteins
What is the function of the rough endoplasmic reticulum
Provide large synthesis of glycoproteins, provide pathway for their transport through cell
What is the function of the smooth endoplasmic reticulum
Synthesis, store and transport lipids and carbs, lacks ribosomes, has more tubular shape
What is the Golgi apparatus
Stacks of membranes that make up flattened sacs ( cisternae) with small round hollow structures called vesicles
What is the Purpose of Golgi apparatus
Proteins and lipids produced in ER are passed through and get modified by adding non protein components to proteins which are carbohydrates and labels them so that they can be correctly sorted. Modified proteins to to the vesicles which move to cell surface, fuse with membrane and release content outside cell.
Function of Golgi apparatus
Add carbs to proteins, produce secretory enzymes, secrete carbs, transport modify and store lipids, form lysosomes
What are lysosomes
Formed when vesicles from GA contain enzymes, contain lysosome hydrolyse bacteria
Function of lysosomes
Hydrolyse material ingested phagocytic cell, release enzymes outside, digest worn out organelles to reuse their chemicals, complete break down cells after they die ( autolysis)
Function of chloroplast
Photosynthesis
Function of chloroplast envelop
Double plasma membrane, highly selective in what enters and leaves
What is the grana
Stacks of about 100 disc like structures called thylakoids
What is the function of grana
Absorbs light. In first stage of photosynthesis
What are thylakoids
Contain chlorophyll pigment, some have tubular extensions ( lamella) which join grana
What is the stroma
Basically the cytoplasm of a chloroplast. For synthesis of sugars
Structure of a cell wall in a plant cell
Consists of microfibrils of cellulose embedded in a matrix
Algal cell walls: cellulose or glycoproteins
Fungi cell wall: chitin( nitrogen containing the polysaccharide)
What is the first stage of mitosis
Interphase
What happens in interphase
Dna replication, cells not dividing, chromosomes not visible
What is the second stage of mitosis
Prophase
What happens during prophase
Chromosomes become visible and breakdown, nucleolus disappears, centrioles move to poles, spindle fibres develop
What is the third phase of mitosis
Metaphase
What happens during metaphase
Spindle fibres form, spindle attach to centromeres of chromosomes, chromosomes line up by being pulled by spindle fibres
What is the fourth phase of mitosis
Anaphase
What happens during anaphase
Centromeres split, chromotids pulled by spindle fibres tk opposite sides, energy for this process given by mitochondria from spindle fibres
What is the fifth phase of mitosis
Telophase
What happens during telophase
Chromosomes fully split, nuclear envelopes reforms and so does nucleolus, spindle fibres disintegrate, chromosomes no longer visible
What is cytokinesis
When the cytoplasm divided to form two cells with genetically identical nuclei
What is binary fission
Happens in prokaryotes eg bacteria. Circular dna replicates, plasmids replicate, cell membrane grows and pinches inwards starting to divide cytoplasm to form two daughter cells, new cell wall forms dividing the original cell and two identical daughter cells form
