cell biology

• eukaryotic cells are complex and include animal ans plant cells. Eukaryotes are organisms that are made up of eukaryotic cells
• cell theory states all living things are composed of one or more cells; the cell is the basic unit of structure and function in living things; new cells arise only from existing cells
• prokaryotic cells are simple, they do not have membrane bound nucleus or other membrane bound organelles.
• prokaryote - bacteria, archaea
• bacteria is an example of prokaryote
• eukaryote - animals, plants, fungi
• bacteria are prokaryotic cells
• bacteria have no nucleus, mitochondria or chloroplasts
• the three domains of life are bacteria, archaea and eukaryota
• archaea are extremophiles which means they live in extreme conditions such as hot springs and acidic environments
• the main difference between prokaryotic and eukaryotic cells is that eukaryotic cells contain a true nucleus while prokaryotic cells don't
• prokaryotic cells are smaller and simpler eg. bacteria. A prokaryote is a prokaryotic cell. it is a single cell organism
• nucleus- contains genetic material and controls cell activities, controls cell division, controls cell growth and development
• ribosomes - site of protein synthesis
• mitochondria - produces energy through respiration
• cytoplasm- it is a gel like substance where chemical reactions take place, where the cell's energy is stored. it contains enzymes to control reactions
• cell membrane- controls what goes in and out of the cell, controls what goes on the cell, holds the cell together
• mitochondria- where aerobic respiration takes place, where most of the energy is released for the cell to work
• ribosomes- where proteins are made up in the cell
• nucleus- stores genetic information (DNA) which tells cells how they function
• rigid cell wall- made up of cellulose, it supports the cell and strengthens it.
• permanent vacuole- contains cell sap (a weak solution of sugar and salt) and is surrounded by a double membrane
• chloroplasts- contain chlorophyll that absorbs light energy from sunlight, converts this into chemical energy stored as glucose.
• stomata- small openings found in leaves, allows gases such as carbon dioxide and oxygen to enter/exit the leaf
• root hair cells- absorb water and mineral salts from soil
• roots anchor plant to ground and store food
• stems support plant and transport water and minerals around plant
• meristematic tissue- undifferentiated cells that can divide to form new plant tissues
• cell division- process where one cell divides to produce two identical daughter cells
• stems support plant and transport substances around plant
• differentiation- when cells become specialised to perform specific functions
• leaves are where photosynthesis takes place
• photosynthesis= plants use light energy to make their own food
• leaves are where photosynthesis takes place
• flowers produce seeds and fruit
• carbon fixation= carbon dioxide enters leaf through stomata and combines with hydrogen atoms to form organic compounds
• apical meristem- located at tips of roots and shoots, responsible for growth of root and stem
• lateral meristem- located between xylem and phloem, responsible for growth of bark and woody stems
• mitosis- type of cell division which produces genetically identical daughter cells
• meiosis- type of cell division which produces gametes (egg or sperm)