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Describe the structure and function of the nucleus Surrounded by a double
membrane called the nuclear envelope, which separates the contents of the nucleus
from the cytoplasm and provides the structural framework of the nucleus. Nuclear
pores allow substances to enter or exit. The nucleolus, made of RNA and proteins,
is the site of ribosome production. The chromatin part of the nucleus possesses all
the genetic information required for the growth, development, reproduction,
metabolism, and behaviour of an organism. Overall the nucleus is responsible for
controlling cell growth and division. The regulation of transcription from mRNA to
protein and controlling the cell's genetic information.
Describe the structure and the function of the rough endoplasmic reticulum (RER)
A series of flattened sacs enclosed by a membrane with ribosomes on the
surface. The RER folds and processes proteins made by the ribosomes.
Describe the structure and the function of the smooth endoplasmic reticulum (SER)
A system of membrane-bound sacs that produces and processes lipids
Describe the structure and the function of the golgi apparatus A series of fluid-
filled, flattened and curved membrane bound sacs with secretory vesicles
surrounding the edges bringing materials to and from. It processes and packages
proteins and lipids to modify for secretion and also produces lysosomes.
Describe the structure and function of the mitochondria Oval-shaped surrounded
by a double membrane, also called the envelope. Folded inner membrane forms cristae
where ATP synthase is specifically produced. The fluid matrix contains
mitochondrial DNA, respiratory enzymes, lipids and proteins. It is the site of
aerobic respiration to produce ATP.
Describe the structure and function of ribosomes Formed of proteins and
ribosomal RNA. Two separate subunits that are assembled in the nucleolus pass
through the nuclear envelope and combine in the cell cytoplasm. Some are found free
in the cytoplasm and others attached to the RER. If bound to the RER, it is
responsible for synthesising proteins that will be exported outside the cell
whereas free ribosomes are primarily the assembly site of proteins that will be
used inside the cell.
Describe the structure and function of chloroplasts Found only in plants cells
and some protists. Surrounded by a double membrane. The inner membrane is
continuous with stacks of flattened membrane sacs called thylakoids whose membranes
contain cholrophyll. Each stack of thylakoids is called a granum where the first
stage of photosynthesis occurs, when wavelengths of light are trapped in
chlorophyll and are used to make ATP. The stroma is a fluid filled matrix where the
second stage of photosynthesis where the energy from ATP is used to make
carbohydrates. The overall function is to be the site of photosynthesis to convert
solar energy into chemical energy.
Describe the structure and function of lysosomes A sac surrounded by a single
membrane containing powerful hydrolytic (digestive) enzymes, keeping them seperate
from the rest of the cell. Also can engulf old cell organelles and foreign matter
and digest them and return them to the cell for reuse. Abundant in phagocytic
cells.
Describe the structure and function of a cell wall made of bundles of cellulose
microfibrils and is on the outside of the plasma membrane. Strong and prevents
plants cells from bursting when turgid. Provides plant cells with strength and
support, helps the cell keep its shape and contributes to the overall strength and
support of the plant. It is permeable so allows solutions to pass through. Fungi
also have a cell wall but it is made of chitin instead of cellulose.
Describe the structure and function of centrioles Consists of two bundles of
microtubules at right angles to each other, made of tubulin protein subunits and
arranged into a cylinder. Before cell divides the spindle made of threads of
tubulin forms from them. Involved in the formation of cilia and undulipodia as they
multiply and line up beneath the cell membrane. Microtubules then sprout out from
them.
Describe the structure and function of cilia and undulipodia Protrusions from
, the cell surrounded by the cell surface membrane. Each contains microtubules and is
formed by centrioles. Epithelial cells lining airways have many hundreds of cilia
that beat and move the layer of mucus. Nearly all cells in the body have one cilium
that acts as an antenna which contains receptors and allows the cell to detect
signals from the immediate environment. Undulipodia enables the spermatozoon to
move, as an extension of the cell. Also known as a flagellum.
Describe the structure and function vacuole Surrounded by a membrane called the
tonoplast and contains fluid. Only plant cells have a large permanent vacuole. It
is filled with water and solutes to maintain cell stability, making cell turgid
when the vacoule pushes against the cell wall, helping to support the overall
plant. Also the fluid contains nutrience storage, contains betalain pigment and
aids in waste disposal.
Describe the structure of cytoskeleton A network of protein structures within
the cytoplasm. Rod-like microfilaments made of subunits of the protein actin.
Straight, cylindrical-shaped microtubules made of protein subunits called tubulin.
Cytoskeletal motor proteins, myosins, kinesins and dyneins are molecular motors.
They function as enzymes, binding to sites and hydrolysing ATP as their energy
source. Also, have intermediate filaments.
Describe the function of cytoskeleton Protein microfilaments give support and
mechanical strength, keeping the cell's shape stable and allow cell movement.
Microtubules provide similar support, form tracks along which motor proteins walk
and drag organelles from one part of the cell to another and also form the spindle
before cell division. Intermediate filaments anchor the nucleus in the cytoplasm
and stablise tissues by extending between cells, enabling cell-to-cell signalling
and allowing cells to adhere to a basement membrane.
Animal cell organelles (10) ribosome, rough endoplasmic reticulum, nuclear
envelope, lysosome, golgi apparatus, plasma membrane, smooth endoplasmic reticulum,
nucleus, nucleolus, mitochondria.
Plant cell organelles (13) ribosome, rough endoplasmic reticulum, nuclear
envelope, golgi apparatus, plasma membrane, smooth endoplasmic reticulum, nucleus,
nucleolus, mitochondria, amyloplast containing starch, chloroplasts, cell wall,
vacuole.
Explain how a light / optical microscope works Light is directed through a thin
layer of biological material on a glass slide, then light is focused through
several lenses so different specimens absorb different amounts and different
wavelengths of light. Reflected light is transmitted to the observer via the
objective lens and eyepiece. When using microscope always start with a low-power
objective lens so it is easier to find the organelle you are looking for and
prevent damage. If image is unclear it may be due to contamination, sample is not
cut thin enough or incorrect focus (so switch to lower power objective lens and use
coarse focus). Use diaphragm for optimum light. A photograph of the image produced
is called a photomicrograph.
Describe how an electron microscope(TEM) works Specimen has to be chemically fixed
and a high energy beam of electrons passes through it after it is stained with
metal oxides. More dense structures appear darker since they absorb more electrons.
Only some electrons pass through and an image is focused onto a fluorescent screen
or photographic plate using magnetic lenses. When photographed this is called an
electron micrograph.
describe how a scanning electron microscope (SEM) works An electron beam is
focused onto the speciman surface using electromagnetic lenses. Reflected electrons
hit a collecting device and are amplified to produce an image on a photographic
plate.
List and describe the features of a light microscope (9) Eyepiece lens usually
x10 or x15 - magnifies the image.Turret rotates to bring objective lenses into
place. Objective lenses (x4 low, x10 medium and x40 high) focuses the image.Stage
where the slide is placed.Diaphragm level controls the amount of light reaching the
object.Condenser is used to vary the intensity of light reaching object.Light
source Fine focus is used to focus high-power objective lenses. Coarse focus is
used to focus low to medium power objective lenses.
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Describe the structure and function of the nucleus Surrounded by a double
membrane called the nuclear envelope, which separates the contents of the nucleus
from the cytoplasm and provides the structural framework of the nucleus. Nuclear
pores allow substances to enter or exit. The nucleolus, made of RNA and proteins,
is the site of ribosome production. The chromatin part of the nucleus possesses all
the genetic information required for the growth, development, reproduction,
metabolism, and behaviour of an organism. Overall the nucleus is responsible for
controlling cell growth and division. The regulation of transcription from mRNA to
protein and controlling the cell's genetic information.
Describe the structure and the function of the rough endoplasmic reticulum (RER)
A series of flattened sacs enclosed by a membrane with ribosomes on the
surface. The RER folds and processes proteins made by the ribosomes.
Describe the structure and the function of the smooth endoplasmic reticulum (SER)
A system of membrane-bound sacs that produces and processes lipids
Describe the structure and the function of the golgi apparatus A series of fluid-
filled, flattened and curved membrane bound sacs with secretory vesicles
surrounding the edges bringing materials to and from. It processes and packages
proteins and lipids to modify for secretion and also produces lysosomes.
Describe the structure and function of the mitochondria Oval-shaped surrounded
by a double membrane, also called the envelope. Folded inner membrane forms cristae
where ATP synthase is specifically produced. The fluid matrix contains
mitochondrial DNA, respiratory enzymes, lipids and proteins. It is the site of
aerobic respiration to produce ATP.
Describe the structure and function of ribosomes Formed of proteins and
ribosomal RNA. Two separate subunits that are assembled in the nucleolus pass
through the nuclear envelope and combine in the cell cytoplasm. Some are found free
in the cytoplasm and others attached to the RER. If bound to the RER, it is
responsible for synthesising proteins that will be exported outside the cell
whereas free ribosomes are primarily the assembly site of proteins that will be
used inside the cell.
Describe the structure and function of chloroplasts Found only in plants cells
and some protists. Surrounded by a double membrane. The inner membrane is
continuous with stacks of flattened membrane sacs called thylakoids whose membranes
contain cholrophyll. Each stack of thylakoids is called a granum where the first
stage of photosynthesis occurs, when wavelengths of light are trapped in
chlorophyll and are used to make ATP. The stroma is a fluid filled matrix where the
second stage of photosynthesis where the energy from ATP is used to make
carbohydrates. The overall function is to be the site of photosynthesis to convert
solar energy into chemical energy.
Describe the structure and function of lysosomes A sac surrounded by a single
membrane containing powerful hydrolytic (digestive) enzymes, keeping them seperate
from the rest of the cell. Also can engulf old cell organelles and foreign matter
and digest them and return them to the cell for reuse. Abundant in phagocytic
cells.
Describe the structure and function of a cell wall made of bundles of cellulose
microfibrils and is on the outside of the plasma membrane. Strong and prevents
plants cells from bursting when turgid. Provides plant cells with strength and
support, helps the cell keep its shape and contributes to the overall strength and
support of the plant. It is permeable so allows solutions to pass through. Fungi
also have a cell wall but it is made of chitin instead of cellulose.
Describe the structure and function of centrioles Consists of two bundles of
microtubules at right angles to each other, made of tubulin protein subunits and
arranged into a cylinder. Before cell divides the spindle made of threads of
tubulin forms from them. Involved in the formation of cilia and undulipodia as they
multiply and line up beneath the cell membrane. Microtubules then sprout out from
them.
Describe the structure and function of cilia and undulipodia Protrusions from
, the cell surrounded by the cell surface membrane. Each contains microtubules and is
formed by centrioles. Epithelial cells lining airways have many hundreds of cilia
that beat and move the layer of mucus. Nearly all cells in the body have one cilium
that acts as an antenna which contains receptors and allows the cell to detect
signals from the immediate environment. Undulipodia enables the spermatozoon to
move, as an extension of the cell. Also known as a flagellum.
Describe the structure and function vacuole Surrounded by a membrane called the
tonoplast and contains fluid. Only plant cells have a large permanent vacuole. It
is filled with water and solutes to maintain cell stability, making cell turgid
when the vacoule pushes against the cell wall, helping to support the overall
plant. Also the fluid contains nutrience storage, contains betalain pigment and
aids in waste disposal.
Describe the structure of cytoskeleton A network of protein structures within
the cytoplasm. Rod-like microfilaments made of subunits of the protein actin.
Straight, cylindrical-shaped microtubules made of protein subunits called tubulin.
Cytoskeletal motor proteins, myosins, kinesins and dyneins are molecular motors.
They function as enzymes, binding to sites and hydrolysing ATP as their energy
source. Also, have intermediate filaments.
Describe the function of cytoskeleton Protein microfilaments give support and
mechanical strength, keeping the cell's shape stable and allow cell movement.
Microtubules provide similar support, form tracks along which motor proteins walk
and drag organelles from one part of the cell to another and also form the spindle
before cell division. Intermediate filaments anchor the nucleus in the cytoplasm
and stablise tissues by extending between cells, enabling cell-to-cell signalling
and allowing cells to adhere to a basement membrane.
Animal cell organelles (10) ribosome, rough endoplasmic reticulum, nuclear
envelope, lysosome, golgi apparatus, plasma membrane, smooth endoplasmic reticulum,
nucleus, nucleolus, mitochondria.
Plant cell organelles (13) ribosome, rough endoplasmic reticulum, nuclear
envelope, golgi apparatus, plasma membrane, smooth endoplasmic reticulum, nucleus,
nucleolus, mitochondria, amyloplast containing starch, chloroplasts, cell wall,
vacuole.
Explain how a light / optical microscope works Light is directed through a thin
layer of biological material on a glass slide, then light is focused through
several lenses so different specimens absorb different amounts and different
wavelengths of light. Reflected light is transmitted to the observer via the
objective lens and eyepiece. When using microscope always start with a low-power
objective lens so it is easier to find the organelle you are looking for and
prevent damage. If image is unclear it may be due to contamination, sample is not
cut thin enough or incorrect focus (so switch to lower power objective lens and use
coarse focus). Use diaphragm for optimum light. A photograph of the image produced
is called a photomicrograph.
Describe how an electron microscope(TEM) works Specimen has to be chemically fixed
and a high energy beam of electrons passes through it after it is stained with
metal oxides. More dense structures appear darker since they absorb more electrons.
Only some electrons pass through and an image is focused onto a fluorescent screen
or photographic plate using magnetic lenses. When photographed this is called an
electron micrograph.
describe how a scanning electron microscope (SEM) works An electron beam is
focused onto the speciman surface using electromagnetic lenses. Reflected electrons
hit a collecting device and are amplified to produce an image on a photographic
plate.
List and describe the features of a light microscope (9) Eyepiece lens usually
x10 or x15 - magnifies the image.Turret rotates to bring objective lenses into
place. Objective lenses (x4 low, x10 medium and x40 high) focuses the image.Stage
where the slide is placed.Diaphragm level controls the amount of light reaching the
object.Condenser is used to vary the intensity of light reaching object.Light
source Fine focus is used to focus high-power objective lenses. Coarse focus is
used to focus low to medium power objective lenses.
