1.2- Cell Structure and Organisation Flashcards
What are eukaryotic cells?
they have a nucleus and membrane bound organelles
What are examples of eukaryotic cells?
animal and plant cells
What are animal and plant cells known as?
eukaryotic cells
What is the nucleus?
its a membrane bound structure that contains the cells genetic information and controls the cells activities
What are nuclear pores?
enable molecules to enter and leave the nucleus, also transport nucleotides
How many parts is there to the nucleus?
4
What are the parts of the nucleus?
nuclear envelope
nucleolus
nucleoplasm
nuclear pores
What is the nuclear envelope?
a double membrane which contains an outer and inner layer that separates the nucleus from the cytoplasm
What is the nucleolus?
small spherical body that manufactures RNA, which is needed to make ribosomes
What is the nucleoplasm?
cytoplasm like material in the inner of the nucleus, where the cell’s DNA is located in the form of chromatin
What is mitochondria?
it has a double membrane structure and is the site of aerobic respiration within the cell
the inner membrane is folded inwards to form extensions called cristae which provide a larger surface surface area for ATP synthesis to occur
What is rough endoplasmic reticulum?
series of flattened sacs enclosed by a membrane with ribosomes on the surface
It folds and processes proteins made on the ribosomes
What is smooth endoplasmic reticulum?
a system of membrane bound sacs and is involved with the synthesis and transport of lipids
What are ribosomes?
small organelles found either free in the cytoplasm or attached to the rough ER
they are the site of protein synthesis
they read RNA to make proteins
What is Golgi body?
series of fluid filled, flattened & curved sacs with vesicles surrounding the edges
it processes and packages proteins and lipids
also produces lysosomes and digestive enzymes
What are the steps of the Golgi body functioning?
- vesicles containing proteins formed by the rough ER fuse at one end of the Golgi sacs
- the protein is modified inside the Golgi sacs
- the modified protein then travels to the cell’s outer plasma membrane where the protein is released to the outside of the cell
this process of releasing the protein is called exocytosis
What are lysosomes?
a vesicle bound by a single membrane which contains digestive enzymes which break down worn out organelles or cells
What are centrioles?
hollow cylinders containing a ring of microtubules arranged at right angles to each other
they form the spindle during cell division
What are chloroplast?
oval-shaped and have a double membrane, the inner and outer
it contains photosynthetic pigments which trap light energy for photosynthesis
the space within the inner membrane is called the stroma
What is a permanent vacuole?
it contains cell sap and stores solutes like glucose, surrounded by a tonoplast membrane
What are prokaryotic cells?
they don’t have any membrane bound organelles and the DNA is suspended freely in the cell
What are the cells walls made out of prokaryotes?
murein
What are the cells walls made out of eukaryotes?
cellulose
what is flagellum?
a tail like structure
which rotates to move the cell
not all prokaryotes have it
What are mesosomes?
Infoldings of the inner membrane which contain enzymes required for respiration
What is capsule?
Protective slimy layer which helps the cell to retain moisture and adhere to surfaces
What are plasmids?
circular pieces of DNA carrying a few genes which occur throughout the cytoplasm
which type of cell is the oldest and simplest?
prokaryotes
What are 2 big differences between euk/prok?
p- free DNA
E- DNA in a nucleus
p- 1-10 um
e- 10-100um
What is one benefit of having DNA housed in a nucleus?
protects the DNA
What is a virus?
non-living structures which consist of nucleic acid
enclosed in a protective protein coat called the capsid
What is a viron?
outside a living cell a virus exists as an inert viron
What are undifferentiated cells known as?
packing cells
What is cell differentiation?
a process by which a cell changes to become specialised
What ways can cells differentiate?
shape of cell
number of a particular organelle
contents of the cell
What is a tissue?
collection of cells that work together to carry out a particular function
What is an epithelial tissue?
forms a continuous layer, covering or lining internal or external surfaces
have no blood vessels but may have nerve endings
sit on a basement membrane made of collagen and protein
vary in shape and complexity
What are the types of epithelial tissue?
cuboidal
ciliated
squamous
What is a cuboidal tissue?
cuboidal shape and has a spherical nucleus
found in the ducts of glands, lining of kidney tubules and small intestine
What is ciliated tissue?
columnar shape
found in the respiratory duct and the Fallopian tubes of women
transports substances like mucus in the bronchi/ ova in the fallopian
What is Squamous tissue?
flattened cells on a basement membrane
form the walls of the alveoli and line Bowman’s capsule in the kidney nephron
What are the types of muscle tissue?
smooth
skeletal
cardiac
What is smooth muscle?
individual spindle-shaped cells that can contract rhythmically, but less powerful than skeletal
found in the skin, walls of blood vessels, digestive and respiratory tracts
as you cannot control this muscle it is called a involuntary muscle
stripes are not visible so is an unstriated muscle
What is Skeletal muscle?
attached to bones and generates movement in mammals
it has bands of long fibres which can contract powerfully but can tire easily
you can control when to contract so is called voluntary muscle
stripes are visible using a microscope so is a striated muscle
What is Cardiac muscle?
only found in the heart
its structure and properties are between smooth and skeletal muscle
striated muscle but lack the long fibres
contract rhythmically, without any stimulation from nerves or hormones, these can modify contractions
do not tire
What is connective tissue?
connect, support or separate tissues and organs
What are the types of connective tissue?
areolar
collagen
ligaments
adipose
What is areolar?
found under the skin
connects organs and tissues together
What is collagen?
forms tendons which connect muscles to bones
What is ligament?
ligaments which connect bones are elastic tissue
What is adipose?
composed of fatty cells
found under the skin and around organs
it’s an energy store, thermal insulator and protects delicate organs
What are organs?
made of several tissues working together to perform a specific function
What organs are in the digestive system?
stomach, ileum
What organs are in the excretory system?
kidney, bladder
What organs are in the skeletal system?
cranium, femur
What organs are in the circulatory system?
heart, aorta
What organs are in the reproductive system?
ovary, testes
What organs are in the respiratory system?
trachea, lung
What organs are in the nervous system?
brain, spinal cord