Cell Organelles & Tissues Flashcards
What does the nucleus do?
Carries the DNA code for amino acid sequences
What does the nuclear envelope do?
Separates the genetic material from the cytoplasm
What is the function of the nuclear pore?
Allows transport of MRNA (messenger ribonucleic acid)
What is the function of the nucleolus?
Synthesis of ribosomes
Name some important parts of a ribosomes structure?
- consists of two subunits ( large & small subunit)
- can be free or attached to rough endoplasmic reticulum
What is a ribosome funcion?
Protein synthesis
Describe the structure of the rough endoplasmic reticulum
- forms a system of flattened sacks (cisternae) which are continuos with the nuclear membrane or may link to Golgi apparatus
- RER has ribosomes attached
Briefly describe the structure of rough endoplasmic reticulum
To transport the proteins synthesized by ribosomes
What are organelles?
Specialized structures living within a cell
What is the function of Golgi apparatus?
Vesicles transport proteins to Golgi body to be modified and packaged. The modified proteins are then packaged into vesicles to be transported around the cell or out of the cell
Describe the function of centrioles
Used in spindle formation (microtubes) in cell division
Describe the function of vesicles in animal cells
Act as a contractile vacuole to maintain osmotic pressure
Describe the function of vesicles in plant cells
Storage of ions and organic molecules e.g protein and maintaing osmotic pressure
Describe the function of the permanent vacuole
Break down complex molecules, store nutrients & non nutrient chemicals and help maintain pressure within a cell
What is the function of the cell wall?
Provides strength and support and it is freely permeable to water
Describe the function of the plasmodesmata
- Exchange of large organic materials via cytoplasmic streaming.
- Allows communication between adjacent cells
What is the function of lysosomes?
- Contain and isolate digestive enzymes
- digestion of materials taken into the cells
Describe the structure of lysosomes
Small vacuoles formed when small portions of the Golgi body are pinched off
Describe the function of chloroplast
Site of photosynthesis
Describe the structure of chloroplasts
- double membrane
- contains thylakoids which forms sacks called granum
Define thylakoid
each of a number of flattened sacs inside a chloroplast
What are cisterna?
A flattened membrane disk that makes up the endoplasmic reticulum and Golgi apparatus.
What does ATP stand for?
Adenosine triphosphate
Describe the structure of plasmodesmata
A narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells
What organelles do a typical prokaryote cell contain?
- cytoplasm
- capsule
- flagellum
- bacterial chromosome
- plasma membrane
- cell wall
- mesosome
- ribosome
- unfolding of membrane
What is the function of striated (skeletal) muscle?
- attached mainly to bones and skin and is responsible for the mobility of the limbs
What is the function of smooth muscle?
- regulates airflow in lungs
- in arteries & veins they are responsible for regulating blood pressure
- shrinking the size of the pupil
- in bladder to push out urine
Define specialised cell?
Some cells are modified to carry our a particular function
What is a tissue?
A tissue is an ensemble of similar cells from the same origin that together carry out a specific function e.g muscle
What are organs?
They are formed by grouping together particular tissues e.g lungs
List the organelles found only in animal cells?
- centrioles
- lysosome
List the organelles found only in plant cells
- chloroplasts
- cellulose cell wall
- permanent vacuole
List all the organelles found in both plant and animal cells
- nucleus
- cytoplasm
- ER
- vesicles
What are the main differences between prokaryotic and eukaryotic cells?
- prokaryotic cell walls are made out of peptidoglycen (murein) whereas eukaryote cells are made of chitin
- DNA is circular in prokaryotic cells and linear in eukaryotic cells
- cell membrane may have unfolding called mesosome and eukaryotes do not
What is connective tissue called?
Collagen
What is the function of connective tissue?
It is a type of protein fiver that provides strength and cushioning to many different areas of the body
What is the function of cuboidal epithelia?
Cuboidal epithelium is found in organs specials for secretion and those are specialised for diffusion. These cells provide protection
What is the function of ciliates epithelia?
To move secretions and foreign bodies away with certain direction of rapid wave like motions from the hair like structures that cover their free surfaces
What is the function of a virus?
It is composed of a genome, Casper and viral envelope. They are a cellular non-living organisms
What are the 4 main functions of the internal cell membranes around the organelles?
- passive osmosis and diffusion
- transporting of proteins and nutrients
- endocytosis: absorption of molecules
- excytosis: removing nutrients through the partially permeable membrane
Name some of the components of a chloroplast
- membrane
- stroma
- granum
- Inner/outer membrane
- thylakoid
- intergranel lamellar
- circle of DNA
Name some of the components of a mitochondria
- inner/outer membrane
- matrix
- ribosomes
- cristae
What is the equation for magnification
Magnification = image size X actual size
Name some of the components of a virus
- Lipid bilayer
- protein coats
- reverse transcriptase enzymes
- RNA & DNA (genetic material)
- envelope glycoprotein
Describe epithelial tissue
- lining tissue, covers the surface of organs, cavities and tubes
- cells packed closely together
- rest on basement membrane
Structure of squamous epithelium
- cells are thin and smooth
Location of squamous epithelium
- cheek cells
- in lungs
Function of squamous epithelium
Provide a short diffusion pathway
Structure of cuboidal epithelial cells
Box shaped
Function of cuboidal cells
Absorption and secretion
Location of cuboidal epithelial cells
- kidney tubule
Structure of columnar epithelial
- Cells are column shaped
- some cells have cilia, some have microvilli
Function of columnar epithelial
- wafting pathogens
- absorption
Location of culumnar epithelial
- small intestine
- respiratory system
Describe muscle tissue
- muscle tissues are all able to shorten their length (they can contract)
- they are three types muscle tissue: skeletal (striated) smooth and cardiac
- inside the cells are protein fibres made of actin & myosin which slide past each other to shorten the cell
Describe the structure of skeletal muscle
- Muscle cells are joined together to form fibres
- the striated (stripes) are caused by overlapping protein molecules in the cells
Describe the function of skeletal muscle
- Used to move organisms
- support soft tissue
- maintain posture
Location of skeletal muscle
- bones (by tendents)
Describe the structure of smooth muscle
- unstriated individual cells which can shorten in length
Describe the function of smooth muscle
Involuntary muscle movements
Describe the location of smooth muscle
- urinary tract
- eyes
- digestive system (intestine)
Describe the structure of cardiac muscle
- the fibres are striated and branched
- are attached at their ends to adjoining fibres by thick plasma membrane called intercalated discs
Describe the function of cardiac muscle
Pump heart
Where is the location of cardiac muscle
Heart
What is the function of connective tissue?
- To connect, support or separate tissues and organs
- It contains elastic and collagen fibres in an extracellular fluid or matrix
- Between the fibres are fat-storing cells (adipocytes) and cells of the immune system
What is an organ?
- An organ comprises several tissues working together, performing a specific function
- In humans, for example, the eye contains nervous, connective, muscle and epithelial tissues and is the organ of sight
- In plants, the leaf contains epidermal tissue, vascular tissue and packing or ‘ground’ tissue between the vascular bundles, which is specialised for photosynthesis
What is an organ system?
-An organ system is a group of organs working together with a particular role
define organism
All the systems of the body work together, making an organism
