cells Flashcards
what are cells?
cells are the basic unit of life, chemical reactions take place in the cell to keep the organism alive, cells can carry out basic life process like reproduction and respiration
what type of organism are there?
- multicellular ( humans, animals )
- unicellular ( yeast, amoeba, and bacteria )
what are unicellular organisms?
unicellular organisms are only made up of 1 cell
what are multicellular organism?
multicellular organism is made up of many different types of cells. They come in different sizes, different shapes and they perform different functions. The cells have similar characteristics
What are the two type of microscopes?
- light microscopes
- electron microscopes
characteristics of microscopes:
- light microscopes
provide relatively low resolution when it is enough, used to stud living cells - electron microscopes
provide higher resolution images and higher magnification, cannot be used to study living cells ( protoplasm and some organelles like mitochondria and ribosomes are able to seen through the electron microscopes )
what is protoplasm?
protoplasm is a living material that can bel found in every living cell. It is a jelly-like substance which consist of cytoplasm, nucleus and cell membrane. Protoplasm can be studied through both light and electron microscope
definition of nucleus.
Nucleus:
1. controls all cell activities taking place in the cell
2. contains deoxyribonucleic acid ( DNA ) which is passed down from parents to offspring
3. nucleus is essential for cell division
definition of cytoplasm.
cytoplasm:
1. cytoplasm is a jelly-like substance
2. the site where most of the chemical reactions take place in the cell
3. contains organelles which are membrane bound specialized structure which performs specific functions
definition of cell membrane.
cell membrane:
1. partially permeable ( only allow certain substances to pass through )
2. controls the movement of substances in and out of the cell
3. also known as plasma membrane
definition of chloroplast.
chloroplast:
1. chloroplast can be found in the cytoplasm of plant cells
2. contains a green pigment ( chlorophyll )
3. traps light to photosynthesize
definition of cell wall.
cell wall:
1. cell wall is full permeable ( allows all substances to pass through )
2. only found in plant cell
3. helps to support the cell by giving it a regular shape
4. protects the cell from injury
5. made up cellulose
definition of vacuole.
vacuole:
1. has high water content
2. stores water, nutrients and mineral salts
plant cell = one central vacuole
animal cell = many small vacuole
mitochondrion ( singular ) , mitochondria ( plural )
performs aerobic function which breaks down glucose to release energy
ribosomes
1.attached to the membrane or freely
2.synthesize proteins for the cell