1.1 Cells Flashcards
Give examples of prokaryotes.
Unicellular organisms such as bacteria.
________ are the basic building blocks of life. A _____________ organism is made up of one cell, while a ____________ organism is made up of many.
CELLS are the basic building blocks of life. A UNICELLULAR organism is made up of one cell, while a MULTICELLULAR organism is made up of many.
Draw and label an animal cell.
- Ribosomes
- Golgi apparatus
- Lysosomes
- Microvilli
- Mitochondria
- Smooth endoplasmic reticulum
- Cytoplasm
- Cell / plasma membrane
- Nucleolus
- Nucleus
- Rough endoplasmic reticulum
Give an examples of eukaryotes.
Plant and animal cells.
Define a prokaryotic cell.
Prokaryotic means ‘before nucleus’. Prokaryotes have no nucleus and no membrane enclosed organelles.
Draw and label a plant cell
- Ribosomes
- Golgi apparatus
- Lysosomes
- Microvilli
- Mitochondria
- Smooth endoplasmic reticulum
- Cytoplasm
- Cell / plasma membrane
- Nucleolus
- Nucleus
- Rough endoplasmic reticulum
- Chloroplasts
- Large central vacuole
- Cell wall
- Starch grain
Compare and contrast plant and animal cells.
Key differences:
- Cell wall - a cellulose cell wall is only present in plant cells.
- Chloroplasts - not in animal cells.
- Large central vacuole - not in animal cells.
- Carbohydrate storage - starch in plants, glycogen in animals.
Describe the function of the nucleus.
Contains the DNA necessary for controlling the cell including the information for synthesising proteins.
Define a eukaryotic cell.
The name means ‘true nucleus’. Eukaryotes have a nucleus containing the genetic information, and membrane enclosed organelles.
Describe the structure of the nucleus.
The nuclear plasm is surrounded by a double membrane called a nuclear membrane, perforated by nuclear pores. The nucleus contains a nucleolus, and chromatin made from DNA.
Describe the function of mitochondria.
Mitochondria produce energy in the form of ATP via aerobic respiration.
Remember to include examples of what this energy is used for.
Describe the structure of mitochondria.
They are made of a matrix bound by a double membrane. The inner membrane is deeply folded into cristae. The matrix contains lipids, proteins and some DNA.
Explain the structure of mitochondria and it is adapted for its function.
The __________ controls entry and exit of substances.
The __________ is deeply folded to form ______. This increases _________ for respiratory __________.
The OUTER MEMBRANE controls entry and exit of substances.
The INNER MEMBRANE is deeply folded to form CRISTAE. This increases SURFACE AREA for respiratory ENZYMES.
Why did scientists think mitochondria might have originally been a prokaryotic organisms?
They have their own DNA.
They have a double membrane.
What is the ER?
The endoplasmic reticulum is a system of membranes found throughout the cell forming a cytoplasmic skeleton. It is a continuation of the nuclear membrane.
How is the ER structured and how is it adapted for its function?
It is a series of flattened sacs called cisternae. It provides a large surface area for chemical reactions, and a pathway for material transport.
How do the sER and rER differ and what are their functions?
The smooth endoplasmic reticulum synthesises lipids and has no ribosomes on its surface.
The rough endoplasmic reticulum synthesises proteins and is encrusted with ribosomes on its outer surface.
Ribosomes are the __________ organelle, only 25nm in diameter. They can be ____________ or attached to the __________.
They are made of two ___________. A _____________ and a ___________. They are made of ________ synthesised in the _________.
Ribosomes perform __________, making _______ from ______________.
Ribosomes are the SMALLEST organelle, only 25nm in diameter. They can be FREE FLOATING or attached to the ROUGH ENDOPLASMIC RETICULUM.
They are made of two SUB-UNITS. A LARGE SUB-UNIT and a SMALL SUB-UNIT. They are made of RIBOSOMAL RNA synthesised in the NUCLEOLUS. Ribosomes perform PROTEIN SYNTHESIS making PROTEINS from AMINO ACIDS.
Describe the function of the Golgi apparatus.
The Golgi apparatus sorts, processes, modifies and packages proteins and lipids produced by the cell into vesicles. Vesicles may also be used to produce lysosomes in the Golgi.
Describe the structure of the Golgi apparatus.
The Golgi apparatus is composed of flattened sacs made if membranes. The saves are fluid filled and pinch off smaller sacs at their ends - vesicles.
There is usually only ____ Golgi apparatus in each cell. It is well developed in ___________ cells as _____________ must be packaged into _________ to be transported out of the cell.
There is usually only ONE Golgi apparatus in each cell. It is well developed in SECRETORY cells as LARGE MOLECULES must be packaged into VESICLES to be transported out of the cell.
What is the function of vesicles, and how are they suited to this function?
Vesicles allow large, insoluble molecules such as proteins to leave the cell via exocytosis. Vesicles are made of phospholipid bilayer like the cell membrane so they can fuse and excrete the substance outside the cell.
Vesicles may also distribute substances around the cell, or form lysosomes.
What is the function of lysosomes? And which cells may contain many?
Lysosomes are used to break down unwanted structures in the cell such as pathogens or damaged organelles. Phagocytes contain many lysosomes to break down pathogens.
Lysosomes are similar in size to __________. They are bound by a __________ membrane. The have no ________________. They contain a large number of ________ called __________. They are mainly ___________ in an _____ solution. This must be kept separate from the rest if the cell to avoid ____________.
Lysosomes are similar in size to MITOCHONDRIA. They are bound by a SINGLE membrane. The have no INTERNAL STRUCTURE They contain a large number of ENZYMES called LYSOZYMES. They are mainly HYDROLASES in an ACID solution. This must be kept separate from the rest if the cell to avoid DAMAGE.
The cell surface membrane, aka the ________ membrane controls the _________ of substances in and out of the cell. It is made up of _____________________, __________ and _______________, in what can be described as the _____________ model. All cell membranes have the same basic structure, but the ___________ of different molecules differs from cell to cell. This difference in composition is related to the cell’s _______.
The cell surface membrane, aka the PLASMA membrane controls the PASSAGE of substances in and out of the cell. It is made up of PHOSPHOLIPID BILAYER, PROTEINS and CARBOHYDRATES in what can be described as the FLUID MOSAIC model. All cell membranes have the same basic structure, but the PROPORTION of different molecules differs from cell to cell. This difference in composition is related to the cell’s FUNCTION.
__________ are ____________ projections of the cell membrane, which greatly increases its ____________.
MICROVILLI are FINGER-LIKE projections of the cell membrane, which greatly increases its SURFACE AREA.
Explain the structure of the nucleus and how it is adapted to its function.
Double membrane called a _______________ surrounding the _____________. The nuclear membrane is perforated by _____________, which allow the passage of large molecules such as _____ in and out of the nucleus.
The __________ is the site of __________ RNA (rRNA) synthesis. The ribosomal ___________ are synthesised within the nucleus but assembled _____________.
The nucleus contains __________ which is made of DNA (_____________________) coiled around _____________. During cell division, ___________ comes together in thread-like structures called _______________.
Double membrane called a NUCLEAR MEMBRANE surrounding the NUCLEAR PLASM.
The nuclear membrane is perforated by NUCLEAR PORES which allow the passage of large molecules such as RNA in and out of the nucleus.
The Nucleolus is the site of RIBOSOMAL RNA (rRNA) synthesis. The ribosomal SUB-UNITS are synthesised within the nucleus but assembled OUTSIDE THE NUCLEUS.
The nucleus contains CHROMATIN which is made of DNA (DEOXYRIBONUCLEIC ACID) coiled around HISTONES. During cell division, CHROMATIN comes together in thread-like structures called CHROMOSOMES.
Describe the function of a chloroplast.
The chloroplast traps light energy and converts it to chemical energy using chlorophyll.
What might the chemical energy from photosynthesis be used for?
Used to make carbohydrates from CO2 and H2O, and other large structures. Carbohydrates such as glucose can be used in respiration and to make other molecules.
Describe the structure of chloroplasts and how they are adapted to their function.
They have a _________ membrane ______ enough to let _______ through. ___________ are flattened sacks containing _________ required for ________. A stack is called a ________. The ________ is the _____ filled matrix where some ________ reactions occur. _________ grains are present as the energy storage molecule. Chloroplasts gave their own ______ and ______________ to make the __________ needed for photosynthesis.
They have a DOUBLE membrane THIN enough to let LIGHT through. THYLAKOIDS are flattened sacks containing CHLOROPHYLL required for PHOTOSYNTHESIS. A stack is called a GRANUM. The STROMA is the FLUID filled matrix where some PHOTOSYNTHETIC reactions occur. STARCH grains are present as the energy storage molecule. Chloroplasts gave their own DNA and RIBOSOMES to make the ENZYMES needed for photosynthesis.
Why are starch grains used as an energy storage molecule in plants?
It is a polysaccharide, which is insoluble. It does not affect the water potential of the cell, and does not diffuse out.
Chloroplast adaptations.
Large _________________ of _________ to maximise ______________.
Contain _______ to absorb ________. __________ is a ________ pigment, so it ________ most light __________, but it reflects _________.
There is a ________________ to allow ________ and diffusion of _________ in.
Large __________ to absorb _______.
_______ double membrane with a short ____________ for __________ of ______ and _____.
Many located under the ____________ to allow _________ light to be __________.
Optimum _____ and _____________ for _________.
Large SURFACE AREA of THYLAKOIDS to maximise LIGHT ABSORPTION .
Contain CHLOROPHYLL to absorb LIGHT. CHLOROPHYLL is a GREEN pigment, so it ABSORBS most light WAVELENGTHS, but it reflects GREEN.
There is a CONCENTRATION GRADIENT to allow OSMOSIS and diffusion of CO2 in.
Large SURFACE AREA to absorb LIGHT.
THIN double membrane with a short DIFFUSION PATHWAY for DIFFUSION of CO2 and H2O.
Many located under the UPPER EPIDERMIS to allow LOTS OF light to be ABSORBED.
Optimum PH and TEMPERATURE for ENZYMES.
Which organelle contains the most polysaccharide in a plant cell?
Cellulose cell wall.
What is the structure and adaptations of the cellulose cell wall in plants?
It has got very strong ________ bonds so it can _______ stretching and _______ due to _______________. This _________ the the cell against _________.
The cell wall is ________ to most molecules, unlike the __________.
Cells walls of __________ cells are _________ by a ______ layer called the ____________. This acts to ______ the walls together with ________.
It also has _____________, which are _____ in the cell walls that allow materials to ____________ between cells.
What is the structure and adaptations of the cellulose cell wall in plants?
It has got very strong HYDROGEN bonds so it can RESIST stretching and TEARING due to OSMOTIC PRESSURE. This PROTECTS the the cell against LYSIS.
The cell wall is PERMEABLE to most molecules, unlike the CELL MEMBRANE.
Cells walls of ADJACENT cells are SEPARATED by a THIN layer called the MIDDLE LAMELLA. This acts to STICK the walls together with PECTIN.
It also has PLASMODESMATA, which are GAPS in the cell walls that allow materials to TRAVEL between cells.
The plant vacuole contains _________, a _____ solution of _________ and _______. The vacuole can hold up to 90% of ______, and it is responsible for the ________ property which provides _______ to the cell.
The plant vacuole contains CELL SAP, a WEAK solution of SUGAR and SALT. The vacuole can hold up to 90% of WATER, and it is responsible for the TURGIDITY property which provides SUPPORT to the cell.
Draw and label an algae cell.
- Ribosomes
- Flagellum
- Nucleolus
- Nucleus
- Chloroplast
- Golgi apparatus
- Mitochondria
- Centriole
- Starch vacuole
- Cell membrane
- Cellulose cell wall
- Cytoplasm
What are algae?
Algae are single or multicellular organisms that have no roots, stems or leaves, and are often found in water.
Draw and label bacterial cell. Add the function of each organelle.
- Photosynthetic membrane - to conduct photosynthesis.
- Capsule - for protection.
- DNA free in the cytoplasm.
- Free 70s ribosomes.
- Flagellum - for movement.
- Mesosomes - equivalent to mitochondria.
- Pili - hold bacteria together for reproduction and exchange of DNA.
- Plasmid - can be used in genetic engineering.
- Cell wall - made of murein.
- Cell membrane.
Compare and contrast prokaryotic and eukaryotic cells.
DNA - circular and not associated associated with proteins in prokaryotic cells. In eukaryotic cells, DNA is linear and associated with proteins called histones that together form chromosomes
Only eukaryotic cells contain membrane bound organelles.
Nucleus - prokaryotic cells have no ‘true’ nucleus, their DNA is free in the cytoplasm, but can have plasmids. Eukaryotic cells have DNA contained within a nuclear membrane.
Ribosomes - smaller 70s ribosomes in prokaryotic cells, larger 80s is eukaryotic cells.
Many prokaryotic cells have capsules and flagella, but very few eukaryotic cells have them.
Cell wall - murein (glycoprotein) in prokaryotic cells, and cellulose in plant cells.
Draw and label a virus.
- Attachment proteins.
- Capsid.
- Core genetic material - DNA/RNA.
Viruses are _________. (Do not contain _____ or is not made up of ______), and are ___________________. The ______ provides the virus with a __________ outer coat and ________ the viral ___________.
Viruses are ACELLULAR. (Do not contain CELLS or is not made up of CELLS) and are NON-LIVING MICROORGANISMS. The provides the virus with a PROTECTIVE outer coat and SURROUNDS the viral DNA OR RNA.
A group of ______, of common ________, which work together for a ______________ is known as a ________.
A group of ________ which work together for a ___________ is known as an ________.
A group of ________ which work together for a ____________ is known as an ____________.
A group of ________ is an __________.
A group of CELLS, of common ORIGIN, which work together for a COMMON FUNCTION is known as a TISSUE.
A group of TISSUES which work together for a COMMON FUNCTION is known as an ORGAN.
A group of ORGANS which work together for a COMMON FUNCTION is known as an ORGAN SYSTEM.
A group of SYSTEMS is an ORGANISM.
Draw and label the structure of the leaf. Add the function and adaptation of each part.
- Wax cuticle - prevents water loss.
- Upper epidermis - thin to let light through.
- Palisade mesophyll - contains chloroplasts for photosynthesis.
- Spongy mesophyll - contains air spaces for improved gaseous exchange.
- Lower epidermis - has guard cells and stoma.
- Guard cells have chloroplasts to absorb light and perform photosynthesis. They control the stomata size to prevent water loss and allow diffusion of gases in and out. (follows a rough cycle - closed at mid-day to prevent water loss)
How are palisade cells adapted to their purpose?
- They have many chloroplasts to absorb light for photosynthesis.
- They have a permeable cell wall for CO2 to pass in.
- The vacuole pushes chloroplasts to the edge of the cell.
