1 - Cells and Tissues -pages 29 to 43 Flashcards
Name the key organelles found in body cells
Nucleus & Nucleolus
Mitochondria
Ribosomes
Golgi Apparatus
Lysosomes
Rough Endoplasmic Reticulum
Smooth Endoplasmic reticulum
Cytoskeleton
Describe the nucleus
A round structure that contains the bodys genetic information (DNA)
Which body cells do not have a nucleus
Red blood cells
Why are red blood cells non nucleated?
To maximise the space to carry oxygen in the blood
Which organelle is the brain of the cell?
Nucleus
What other organelle does the nucleus contain and what does it produce?
Nucleolus which produces ribonucleic acid (RNA)
What surrounds the nucleus and separates it from the cytoplasm?
A double layered nuclear membrane
What does the nuclear membrane contain that allows substances to move in and out of the nucleus?
Nuclear pores
What other organelle is the nuclear membrane continuous with?
Rough Endo plasmic reticulum
What is a Chromosome and where is it found?
Found in the Nucleus of cells
Thread like structures carrying genetic information (genes)
How many chromosomes are in each cell of the body?
46 or 23 pairs
Except sex cells
Normal body cells are called?
Somatic cells
Sex cells are called?
Gametes
What are the hereditary units called arranged along chromosomes?
Genes
What are Chromosomes formed from
Coiled DNA
What do the 23rd pair of chromosomes do?
Dtermines inheriteance of sex
What are the sex chromosomes for males?
XY
What are the sex chromosomes for females?
XX
What shape does DNA form?
A double helix
Name the proteins the double helix coils around
Histones
Name the mass of string like fibres DNA is organised into
Chromatin
Before cellular division Chromatin condenses into 46 individual molecules called..
What is a gene?
A sub section of DNA that acts as an instruction to make proteins.
What information does a gene hold?
To build and maintain cells
To pass genetic traits
How many proteins does one gene code produce?
one
Are all genes switched on?
No. Only certain genes are switched on depending on the cells job.
What is the cytoskeleton?
A network of protein filaments which extends through the cytosol
What does the cytoskeleton protein filaments assis in?
Generate cell movement
Physical support and determines cell shape
Cell division - moves chromosomes apart
Describe Mitochondria
Bean Shaped
2nd largest organelle
What is the function of Mitochondria?
The cell powerhouses generating ATP
(Adenosine Triphosphate)
The energy currency of the body.
Where are Mitochondria typically located?
Near where oxygen enters cells
(towards outside)
Name the structures inside of Mitochondria
double layered membrane with a series of folds called ‘CRISTAE’
What is the function of Cristae
Produces a vast surface area for reactions.
Which type of cells are thought to contain the most Mitochondria?
Heart and muscle cells
(use ATP for contraction)
What is the process called in which Mitochondria produce ATP
Aerobic Respiration
What is the function of a Ribosome
They act as the site of protein synthesis
What does the name ‘Ribosome’ reflect?
The high content of RIBONUCLEIC acid (RNA)
Name the two forms of Ribosomes and where they are found?
Mobile - in cytoplasm
Stationary - bound to rough ER
Where do Ribosomes make protein for?
Mobile Ribosomes - for inside cell
Bound to ER - for outside cell
Describe the Endoplasmic Reticulum
A network of membranes in the form of flattened sacs
What can be found on the outer surface of the Rough ER
Ribosomes
What is the function of the Rough ER
Synthesises and transports proteins
What is the function of the smooth Endoplasmic Reticulum?
Synthesises Lipids and Steriod hormones
eg: Testosterone
Cortisol
Oestrogen
What function in the liver do the enzymes of the smooth ER perform?
Detoxify Alcohol and Drugs
What function on muscle cells does the Smooth ER perform
Stores calcium and releases it for muscle contraction
What is the function of the Golgi Apparatus?
Modifies, sorts, packages and transports proteins received from the Rough ER
What does the Golgi look like?
Flattened membranous sacs
How do the proteins leave the Golgi apparatus
They bud off in transport vesicles.
What is the function of Lysosomes?
Vesicles that perform a key role in CELL DIGESTION
What do lysosomes contain?
As many as 60 powerful enzymes - to break down a variety of molecules.
What is the function of a Lysosome?
to recycle worn out organelles
to digest foreign cells
to release enzymes
(eg with sperm to assist egg entry)
