Cells Flashcards
Similarities
Both prokaryotic and eukaryotic cells contain ___
The cell-surface membrane in eukaryotic and prokaryotic cells is made of …
This bilayer is responsible for …
Similarities
Both prokaryotic and eukaryotic cells contain organelles.
The cell-surface membrane in eukaryotic and prokaryotic cells is made of a phospholipid bilayer.
This bilayer is responsible for controlling the passage of substances across exchange surfaces.
Differences
Prokaryotic cells make up ..(e.g. ___).
In contrast, eukaryotic cells make up … e.g. …).
Eukaryotic cells are …
Cells arise from other cells by … in prokaryotic cells and by … in eukaryotic cells.
Differences
Prokaryotic cells make up single-celled prokaryotic organisms (e.g. bacteria).
In contrast, eukaryotic cells make up complex eukaryotic organisms (e.g. animals, plants, fungi and algae).
Eukaryotic cells are larger and more complex than prokaryotic cells.
Cells arise from other cells by binary fission in prokaryotic cells and by mitosis or meiosis in eukaryotic cells.
Animal cell organelles:
Animal cell organelles:
Cytoplasmic membrane Endoplasmic reticulum Ribosomes Nucleus Nucleolus Nuclear membrane Golgi Cytoplasm Mitochondrion
Plant cell
Plant cells contain all the organelles found in animal cells.
Plant cells also possess:
___ (…).
___ (…)
___ (…)
Plant cell
Plant cells contain all the organelles found in animal cells.
Plant cells also possess:
Vacuole (a repository of cell sap).
Chloroplasts (the site of photosynthesis).
Cell wall (made of cellulose and contains plasmodesmata, through which cells exchange substances with each other).
Fungal cells are similar to plant cells except … and …
Fungal cells are similar to plant cells except there are no chloroplasts in fungal cells and the cell wall is made from chitin instead of cellulose.
… This is called specialisation. Specialised cells are then …
In complex multicellular organisms, cells gain specific features. This is called specialisation. Specialised cells are then organised into groups to perform a function
Cell specialisation
A cell specialises because …
Examples include:
Muscle cells …
Red blood cells …They also …
Palisade cells …
Cell specialisation
A cell specialises because the shape and contents of a cell help it to carry out its function.
Examples include:
Muscle cells are very active so contain lots of mitochondria in order to produce ATP.
Red blood cells have a biconcave shape and no nucleus to maximise space to carry oxygen. They also have lots of haemoglobin.
Palisade cells have a long, upright shape and contain chlorophyll to absorb light for photosynthesis.
Cell organisation
Specialised cells are organised into ____, ___ into ___ and ___ into …
Tissues (e.g. …).
Organs (e.g. …).
Organ systems (e.g. …).
Cell organisation
Specialised cells are organised into tissues, tissues into organs and organs into organ systems.
Tissues (e.g. muscle tissue, xylem tissue).
Organs (e.g. the animal heart or plant leaf).
Organ systems (e.g. the female reproductive system, which includes the uterus, ovaries, mammary glands and breasts).
Structure of the plasma membrane
The plasma membrane is made from a …
A phospholipid is a …
Plasma membranes have …
These proteins can … This means that …
Structure of the plasma membrane
The plasma membrane is made from a phospholipid bilayer.
A phospholipid is a lipid molecule with glycerol, two fatty acid chains, and a phosphate-containing group.
Plasma membranes have proteins and cholesterol embedded in them.
These proteins can act as receptors. This means that the cell can respond to the external environment of the cell.
Function of the plasma membrane
The plasma membrane controls …
Waste products (e.g. ___ and ___) leave …
Function of the plasma membrane
The plasma membrane controls the passage of organic molecules, ions, water, and oxygen into and out of the cell.
Waste products (e.g. carbon dioxide and ammonia) leave the cell by passing through the plasma membrane.
Structure of the cytoplasm
Cytoplasm is made up of ____ suspended in …
__% of the cytoplasm is …
The cytoplasm also …
Structure of the cytoplasm
Cytoplasm is made up of organelles suspended in the gel-like cytosol.
70% of the cytoplasm is made up of water.
The cytoplasm also contains proteins, sugars, ions and fatty acids.
Functions of the cytoplasm
… take place in the cytoplasm.
Different organelles …
It is important to remember that …
Organelles are NOT cells even though …
Functions of the cytoplasm
Many metabolic reactions take place in the cytoplasm.
Different organelles perform specific functions within the cytoplasm.
It is important to remember that organelles are parts of a cell.
Organelles are NOT cells even though they often surrounded by membranes.
Structure of the nuclear envelope
The nuclear envelope is …
Both the inner and outer membranes of the nuclear envelope are …
Structure of the nuclear envelope
The nuclear envelope is a double-membrane structure that has a number of pores.
Both the inner and outer membranes of the nuclear envelope are phospholipid bilayers.
Function of the nuclear envelope
The pores in the nuclear envelope control …
Function of the nuclear envelope
The pores in the nuclear envelope control the passage of ions, molecules and RNA between the nucleoplasm and cytoplasm.
Structure of the nucleus
The nucleoplasm is …. where we find …
In ____, the nucleus contains …
There is an area within the nucleus called the ____ (plural = nucleoli).
Structure of the nucleus
The nucleoplasm is the semi-solid fluid inside the nucleus, where we find the chromatin and the nucleolus.
In eukaryotes, the nucleus contains linear chromosomes that are made up of DNA.
There is an area within the nucleus called the nucleolus (plural = nucleoli).
Function of the nucleus
The nucleus controls …
DNA in the nucleus contains …
___ ___ is joined together with associated proteins … to
Function of the nucleus
The nucleus controls the actions of the cell.
DNA in the nucleus contains instructions for the synthesis of proteins.
Ribosomal RNA is joined together with associated proteins in the nucleolus to assemble the ribosomal subunits.
Mitochondria produce … via …
Chloroplasts are … that …
Mitochondria produce adenosine triphosphate (ATP) via aerobic respiration.
Chloroplasts are plant cell organelles that carry out photosynthesis.
Structure of mitochondria
Mitochondria are … that have …
Each membrane is …
The inner layer of the membrane …
The area surrounded by the folds is …
The mitochondrial matrix contains …
Structure of mitochondria
Mitochondria are oval-shaped, double-membrane organelles that have their own ribosomes and DNA.
Each membrane is a phospholipid bilayer embedded with proteins.
The inner layer of the membrane has folds called cristae.
The area surrounded by the folds is called the mitochondrial matrix.
The mitochondrial matrix contains enzymes used for respiration.
Function of mitochondria
Mitochondria make ATP via aerobic respiration.
Muscle cells have a very high concentration of ___ because … and …
Function of mitochondria
Mitochondria make ATP via aerobic respiration.
Muscle cells have a very high concentration of mitochondria because they are highly active and need a lot of energy to keep the body moving.
Structure of chloroplasts
Chloroplasts have … and have …
The space enclosed by the inner membrane contains a set of … and … called ___
Each stack of thylakoids is called a ___(plural = grana).
Grana are linked by ____
Lamellae are …
The fluid enclosed by the inner membrane that surrounds the grana is called the ___
Structure of chloroplasts
Chloroplasts have their own DNA, ribosomes and have inner and outer membranes.
The space enclosed by the inner membrane contains a set of interconnected and stacked fluid-filled membrane sacs called thylakoids.
Each stack of thylakoids is called a granum (plural = grana).
Grana are linked by lamellae.
Lamellae are flat, thin parts of thylakoid membrane.
The fluid enclosed by the inner membrane that surrounds the grana is called the stroma.
Function of chloroplasts
Photosynthesis is the series of …
This process happens in ___ and …
Chloroplasts are found in … but not in …
Function of chloroplasts
Photosynthesis is the series of reactions that use carbon dioxide, water and light energy to make glucose and oxygen.
This process happens in chloroplasts and allows plants to make their own food (e.g. sugars).
Chloroplasts are found in plant and algal cells but not in animal or fungal cells.
Structure of Golgi apparatus
The Golgi apparatus is …
Structure of Golgi apparatus
The Golgi apparatus is a series of flattened membranous sacs.
Function of Golgi apparatus
Transport vesicles form at … and fuse with
The transport vesicles empty ___ and ___ into …
As the ___ and ___ travel through .., they are … so that …
Function of Golgi apparatus
Transport vesicles form at the endoplasmic reticulum and fuse with the Golgi apparatus.
The transport vesicles empty proteins and lipids into the lumen of the Golgi apparatus.
As the proteins and lipids travel through the Golgi, they are sorted, packaged and tagged so that they can be sent to the right place.
Structure of Golgi vesicles
Golgi vesicles … located in …
They are ___, ___ and are seen in a high ___ near the ..
___ are a type of Golgi vesicle.
Structure of Golgi vesicles
Golgi vesicles are membrane-bound, fluid-filled vesicles located in the cytoplasm.
They are small, round and are seen in a high density near the edges of the sacs.
Lysosomes are a type of Golgi vesicle.
Function of Golgi vesicles
Golgi vesicles …
___ are a special type of Golgi vesicle.
They contain enzymes called ___
Lysozymes aid the …
Function of Golgi vesicles
Golgi vesicles store and transport modified proteins and lipids from the Golgi apparatus to target cells.
Lysosomes are a special type of Golgi vesicle.
They contain enzymes called lysozymes.
Lysozymes aid the breakdown of proteins, polysaccharides, lipids, nucleic acids and old organelles.
Ribosomes and the Endoplasmic Reticulum
Proteins are made in ___
Proteins may then be … by the …
The smooth endoplasmic reticulum makes and processes ___
Ribosomes and the Endoplasmic Reticulum
Proteins are made in ribosomes.
Proteins may then be folded and processed by the rough endoplasmic reticulum (RER).
The smooth endoplasmic reticulum makes and processes lipids.
Structure of ribosomes
Ribosomes can be … in the cytoplasm or attached to …
Ribosomes are very ___ organelles made of …
This means that ribosomes are not covered by …
Structure of ribosomes
Ribosomes can be free floating in the cytoplasm or attached to the cytoplasmic side of the endoplasmic reticulum (ER).
Ribosomes are very small organelles made of protein subunits.
This means that ribosomes are not covered by a membrane.
Function of ribosomes
Ribosomes are in charge of …
… is an essential function of all cells.
This is why ribosomes are found in practically every cell.
Function of ribosomes
Ribosomes are in charge of protein synthesis.
Protein synthesis is an essential function of all cells.
This is why ribosomes are found in practically every cell.
Structure of the ER
The ER is a series of …
The membrane of the ER is a … embedded with ___
The smooth ER (SER) membrane has no ___ but the rough ER (RER) membrane has many ___ on it’s ___
Structure of the ER
The ER is a series of interconnected membranous sacs and tubules.
The membrane of the ER is a phospholipid bilayer embedded with proteins.
The smooth ER (SER) membrane has no ribosomes but the rough ER (RER) membrane has many ribosomes on its surface.
Function of the RER and SER
The RER is responsible for …
The SER is responsible for …
Function of the RER and SER
The RER is responsible for processing and folding proteins.
The SER is responsible for making and processing lipids.
Cell Wall and Cell Vacuole
The cell wall is a structure external to …
Cell vacuoles are found in …
Cell Wall and Cell Vacuole
The cell wall is a structure external to the plasma membrane.
Cell vacuoles are found in plant cell cytoplasm.
Structure of cell walls
The cell wall is a … that ___ the cell.
… cells all have cell walls.
The major organic molecule in fungal cell walls is ___
Plant and algal cell walls are made of ___
Cellulose is a ___ made up of glucose units.
Structure of cell walls
The cell wall is a rigid covering that protects the cell.
Plant, fungal and algal cells all have cell walls.
The major organic molecule in fungal cell walls is chitin.
Plant and algal cell walls are made of cellulose.
Cellulose is a polysaccharide made up of glucose units.
Function of cell walls
The cell wall provides … and gives ___ to the cell.
Function of cell walls
The cell wall provides structural support and gives shape to the cell.
Structure of cell vacuoles
Plant cells each have a large … that occupies most of the area of the cell.
These vacuoles are surrounded by a membrane called the ___ and contain a ___ solution of …
Cell vacuoles are found in the cytoplasm of ___ cells but are NOT present in ___ cells.
Structure of cell vacuoles
Plant cells each have a large central vacuole that occupies most of the area of the cell.
These vacuoles are surrounded by a membrane called the tonoplast and contain a weak solution of salts and sugars called cell sap.
Cell vacuoles are found in the cytoplasm of plant cells but are NOT present in animal cells.
Function of cell vacuoles
The central vacuole allows the cell to remain ___
When the central vacuole holds more water, the vacuole … and …
This stops the plant from …
The vacuole also isolates … that are unwanted by the rest of the cell.
Function of cell vacuoles
The central vacuole allows the cell to remain rigid.
When the central vacuole holds more water, the vacuole pushes against the cell wall and pressure is maintained.
This stops the plant from wilting.
The vacuole also isolates certain chemicals that are unwanted by the rest of the cell.
Prokaryotic Cells
Prokaryotic cells have some features that are also found in eukaryotic cells.
Prokaryotic cells may also contain …
Prokaryotic Cells
Prokaryotic cells have some features that are also found in eukaryotic cells.
Prokaryotic cells may also contain plasmids, a capsule and one or more flagella.
Prokaryotes vs eukaryotes
Features common to these types of cells are: (3)
So, the main difference in terms of organelles is that prokaryotes do NOT have …
Prokaryotes vs eukaryotes
Features common to these types of cells are:
A plasma membrane.
Cytoplasm.
DNA.
Ribosomes (ribosomes are smaller in prokaryotes).
So, the main difference in terms of organelles is that prokaryotes do NOT have any membrane-bound organelles (e.g. nucleus, mitochondria, Golgi apparatus etc.).
DNA in prokaryotes
Prokaryotic DNA is found as a … in the ___
Some prokaryotes have smaller loops of DNA called ___ that are not part of the …
Bacteria can exchange ___ with other bacteria, sometimes receiving … that the recipient can add to their ..
… is one trait that often spreads through a bacterial colony through plasmid exchange.
DNA in prokaryotes
Prokaryotic DNA is found as a circular molecule in the cytoplasm.
Some prokaryotes have smaller loops of DNA called plasmids that are not part of the main circular DNA molecule.
Bacteria can exchange plasmids with other bacteria, sometimes receiving beneficial new genes that the recipient can add to their chromosomal DNA.
Antibiotic resistance is one trait that often spreads through a bacterial colony through plasmid exchange.
Capsule
The capsule enables prokaryotic cells to …
Capsule
The capsule enables prokaryotic cells to attach to surfaces in its environment.
Flagella, pili and fimbriae
Some prokaryotes have flagella, pili, or fimbriae:
Flagella are tail-like and used for locomotion.
Some prokaryotes have none and others have more than one.
Pili are used to exchange genetic material during a type of reproduction called conjugation.
Fimbriae are used by bacteria to attach to a host cell.
Flagella, pili and fimbriae
Some prokaryotes have flagella, pili, or fimbriae:
Flagella are tail-like and used for locomotion.
Some prokaryotes have none and others have more than one.
Pili are used to exchange genetic material during a type of reproduction called conjugation.
Fimbriae are used by bacteria to attach to a host cell.
Binary Fission
Prokaryotes, such as bacteria, replicate by …
For ___ organisms, cell division is the only method to produce new individuals.
Binary Fission
Prokaryotes, such as bacteria, replicate by binary fission.
For unicellular organisms, cell division is the only method to produce new individuals.
