Cell Biology Flashcards
What is a eukaryote?
A eukaryote is a cell that contains its genetic information enclosed in a nucleus. Typically animal and plant cells.
What is a prokaryote?
A prokaryote is a microscopic organism which contains no distinct nucleus, and has free DNA, and no membrane bound organelles.
What is in eukaryotes that isn’t in prokaryotes?
Nucleus, membrane bound organelles
What is a lysosome?
A specialised vesicle.
What is the structure and function of a lysosome?
Structure- no sub organelle, fluid-filled sac
Function- contains hydrologic enzymes, digests invading pathogens ALSO digests worn out components of cell (“suicide-sack”)
Describe the structure and function of the nuclear envelope
Structure- double membrane and contains pores
Function- pores control what enters and leaves nucleus
Describe the structure and function of the nucleolus
Structure- contains RNA, ribosomal DNA and ribosomal proteins
Function- produces ribosomes, contains
Describe the structure and function of the nucleus
Structure- made of chromatin (a complex structure composed of DNA and proteins called histones) , chromatin coils to form chromosomes
Function- controls cells activities
Describe the structure and function of ribosomes
Structure- float free in the cytoplasm OR rough ER, made of two subunits and proteins and RNA
Function- site of protein synthesis
What is mitochondria?
It is a membrane bound organelle in the cytoplasm of eukaryotes, and is the site of respiration.
Describe the structure and function of the rough ER
Structure – fluid filled sac surrounded by a membrane studied with ribosomes
Function – processes and fold proteins
Describe the structure and function of the Smooth Endoplasmic Reticulum (smooth ER)
Structure- membranes enclosing fluid filled sacs
Function- synthesis and processes lipids and carbohydrates
Describe and explain the structure/functional of the Golgi Apparatus
Structure – membrane enclosed flattened sacs
- vesicles at edge for transportation
Function - processes and packages proteins and lipids and sends them off to vesicles to be secreted, makes lysosomes
Describe the structure and function of the vesicle
S- fluid filled sac
F- transports substances in and out of cells via plasma membrane
What are the 4 parts of mitochondria?
Outer / inner membrane
Cristal
Matrix
Describe the structure and function of the mitochondria
S- double membrane
- highly folded by cristae TO INCREASE S.A
- matrix contains enzymes for respiration
F- site of respiration
- contains maternal DNA
What are the parts of chloroplasts?
- double membrane
- granum / grana
- stroma
- lamellae
Describe the structure and function of the chloroplast
S — double membrane
- thylakoids membranes stacked up called grana
-grana connected by pieces of thylakoid membrane called lamellae
F — site of photosynthesis = some in grana, some in thick liquid called stroma
What do chloroplasts, like mitochondria, contain?
DNA, and contain ribosomes in stroma
Describe the structure and function of the cell wall.
Structure - cellulose in plants, peptidoglycan in prokarytotes, chitin in fungi
Function- keeps cell TURGUD, keeps cell UPRIGHT, prevents cell BURSTING.
Describe the structure and function plasma membrane.
Structure - Phospholipid bilayer, with integral proteins
Function - regulates movement of substances in and out of cell
What is it called when organelles in a cell work together to carry out a specific function? Give example.
Division of Labour
protein synthesis
Describe the structure and function of the centriole
Structure- small hollow cylinders made opus of microtubules
Function- involved in separation of chromosomes in cell division
Describe the process of protein synthesis inside a cell, how do the organelles work together?
,
How do vesicles transport substance out of the cell membrane ?
They fuse with the plasma membrane
What is the cytoskeleton?
A network of protein fibres, actin filaments and microtubules within the cytoplasm.
What are the three types of protein fibres in the cytoskeleton?
Microfilaments
Microtubules
Intermediate Fibres
Describe the structure and function of microfilaments?
Structure— contractile fibres made up of protein called actin
Function— responsible for cell movement and cell contraction during cytokinesis
Describe the structure and function of microtubules
Structure— globular tubulin proteins
Function— act as track for vesicles, also polymerise to forms spindle fibres
Describe the structure and function of intermediate fibres
Structure— various proteins
Function— mechanical strength to cell, and maintains cells integrity (togetherness of organelles/ otherwise fall apart)
Name four things secreted by the cell into the blood
-insulin
-collagen
-mucus
-enzymes
etc.
How do the structures of microfilaments and microtubules allow them to be involved in the movement of cells but intermediate fibres are not?
Microfilaments are composed of acting which is contractile. Microtubules have tubal in which polymerises and this leads to a change in length of the filament and results in movement of cells. Intermediate fibres have fixed lengths for stability.
Name different types of staining
Differential staining
immuno staining
Describe the purpose of differential staining
A dye or stain is used to differentiate one component or cellular structure from another
Why is staining used in microscopy?
Staining provides contrast as different organelles absorb stain differently.
Suggest why all measurements should be converted into the same units before calculation
– Simplifies the calculation
– reduces errors
What is the function of the cytoskeleton?
— necessary for the shape and stability of the cell
— controls cell movement and movement of the cells organelles (track)
— provides mechanical support
