2.1 Cell Structure- Eukaryotic Flashcards
Cell Surface Membrane (function)
Regulates the movement of substances into and out of the cell.
It has receptor molecules on the surface in order to respond to chemicals (eg hormones).
Nucleus (function)
Controls production of mRNA and tRNA and so protein synthesis
Retains genetic material f the cell as DNA and chromosomes
Manufactures ribosomal RNA and ribosomes
Mitochondria (function)
The site of aerobic respiration which produces ATP (krebs cycle and oxidative phosphorylation)
The matrix contains the enzymes involved in respiration
Chloroplasts (function)
The site of photosynthesis
Chlorophyll absorbs light energy and uses this light energy to synthesise glucose
Golgi Apparatus (function)
Processes, packages and transports polypeptides and lipids in preparation for exocytosis
They’re transported in vesicles
Lysosomes (function)
A vesicle containing the digestive enzyme lysosome
Hydrolyse invading cells like bacteria
Releases enzymes to outside the cell (exocytosis) to destroy material around the cell
Digest worn out cells so chemical components can be used again
Break down cells complement when they die (autolysis)
Ribosomes (function)
The site of protein synthesis
mRNA transcribed in the nucleus is translated
Rough Endoplasmic Reticulum (function)
Provides a network of membranes for the transport of polypeptides.
Main site of protein synthesis due to the presence of ribosomes.
Smooth Endoplasmic Reticulum (function)
Synthesises, stores and transports lipids and carbohydrates
Cell Wall (function)
Supports the cell and prevents them from losing their shape (eg due to osmotic pressures)
Cell Vacuole (function)
Helps to maintain pressure in the cell, keeping it turgid
Isolates unwanted chemical inside the cell
Sugars and amino acids are a temporary food store
Pigments colour petals to attract pollinating insects
Eukaryotic Cell (define)
Cell with:
a distinct nucleus
membrane bound organelles
Cell Surface Membrane (structure)
Bilayer of lipids with embedded proteins.
Some lipids and proteins have carbohydrates attached.
Nucleus (structure)
Large organelle with a double membrane called the nuclear envelope with many nuclear pores.
Contains genetic material and one or more nucleolus.
Mitochondria (structure)
Rod shaped organelle with a double membrane
Inner membrane folds to form structured called cristae
Inner fluid compartment is called the matrix
Cristae (define)
The structures formed by the folded inner membrane of the mitochondria
Provide large surface area for the attachment of enzymes and other proteins involved in respiration
Chloroplast (structure)
Disk shaped, flattened organelle with a double membrane
Stacks of membrane inside called thylakoid membranes
Where chlorophyll is found
Golgi Apparatus (structure)
A stack of fluid filled membrane bound sacs (cisternae)
Golgi Vesicles (location)
Often seen seen at the edge of Golgi Apparatus scars.
Potentially anywhere in cytoplasm.
Lysosome (structure)
A type of Golgi Apparatus
A vesicle type with a membrane made of phospholipids
Enzymes are inside the vesicle
Ribosome (structure)
In prokaryotic cells they smaller Eukaryotic: 80S Prokaryotic: 70S Made up of a small and large subunit Made of proteins and RNA Not membrane bound
RER (structure)
A system of membranes enclosing a fluid filled space.
Surface is covered in ribosomes.
SER (structure)
A system of membrane enclosing a fluid filled spcae.
Cell Wall (structure)
Surround cells in plants, algae and fungi
In plants and algae its made from cellulose
In fungi its made from chitin
A thin layer called the middle lamella marks the boundary between adjacent cells walls and cements adjacent cell walls together
Chitin (define)
Polysaccharide that makes up the cell wall of a fungal cell.
Cell vacuole (structure)
A membrane bound organelle in the cytoplasm
Contains cell sap (sugar and salt solution)
The membrane is called the tonoplast
Tonoplast (define)
The surrounding membrane of the vacuole.
Tissue (describe)
A group of similar cells which carry out a specific function. eg muscular tissue/xylem tissue
Organ (describe)
An aggregation of tissues and cells carrying out specific function. eg heart/stem
Organ System (describe)
An aggregation of organs carrying out a specific function efficiently. eg circulatory system/transpiration system
Organism (describe)
Made up of different organ systems working together. eg human/sunflower
What is the nuclear envelope?
Double membrane that surround the nucleus
Controls entry and exit of materials in and out of the nucleus and contains the reactions taking place within it
What are nuclear pores?
Allow passage of large molecules (eg RNA) out of the nucleous
What is nucleoplasm?
Granular, jelly-like material that makes up the bulk of he nucleus
What do chromosomes consist of?
Protein bound, linear DNA
What is the nucleolus?
A small, spherical region within the nucleoplasm
Manufactures ribosomal RNA and assembled the ribosomes
May be more than one in a nucleons
Matrix (define)
Inner fluid of mitochondria
Contains protein, lipids, ribosomes and DNA that allows mitochondria to control the production of its own proteins
Many enzymes involved in respiration are found in the matrix
What are grana?
Stacks of thylakoids in chloroplasts
Thylakoids contain chlorophyll
Location of 1st stage of photosynthesis (light absorption)
What are stroma?
Fluid filled matrix in chloroplasts
Location of 2nd stage of photosynthesis (synthesis of sugars)
Contains other structures like starch grains
How are chloroplasts adapted to efficiently photosynthesise?
Granal membranes provide large surface area for attachment of chlorophyll, electron carriers and enzymes
Stroma fluid contains all the enzymes needed to make sugars in the 2nd stage of photosynthesis
They contain DNA and ribosomes to manufacture some of the proteins needed for photosynthesis
What are the flattened sacs called that make up endoplasmic reticulum?
Cisternae
What is the function of the Golgi apparatus?
Add carbohydrates to proteins to form glycoproteins Produce secretory enzymes Secrete carbohydrates Transport, modify and store lipids Form lysosomes
What happens when the Golgi apparatus has sorted modified proteins and lipids?
They are transported in Golgi vesicles to the cell surface
The vesicles fuse with the membrane and release their contents to the outside
Describe epithelial tissue.
Found in animals
Sheets of cells
Line the surfaces of organs and have a protective secretory function
Eg alveoli in lungs
