B2.1 Supplying the cell Flashcards
Active transport
Movement of molecules against their concentration gradient
Cell cycle
The process of cell growth and division
Concentration gradient
Difference in concentration between two regions
Differentiation
Conversation of cell from unspecialised to specialised
Diffusion
Net movement of particles from a region of high concentration to a region of low concentration
DNA replication
Process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules
Meristems
Growing region of a plant
Mitosis
Process by which body cells divide
Osmosis
Diffusion of water molecules from a region of high concentration to an area of low concentration through a selectively permeable membrane
Specialised
A cell that is adapted to preform a particular function is called a specialised cell
Stem cell
Undifferentiated cell; two main types: adult stem cells and embryonic cells
Embryonic cells
found in embryos. They divide by mitosis to produce all the cells needed to make an organism. Embryonic cells have the ability to differentiate into all cell types.
Adult stem cells
Found in various body tissues such as the brain, bone marrow, skin and liver. They are able to differentiate into specific types of cells, so not as much as embryonic cells. They are used as a repair mechanism for the body.
Sperm cells
A sperm cell is specialised to transfer genetic material from the male to ovum. Its adaptation include: flagellum (to move to the ovum), lots of mitochondria (the energy produced in respiration transferred to the flagellum can move), acrosome (stores digestive enzymes that break down layers of the ovum)
Fat cell
Fat cells are specialised to store fat (store of energy). They are adapted by having a small layer of cytoplasm surrounding the fat reservoir.
Red blood cells
They specialised to transport oxygen around the body. Adaptions include their biconcave disc shape (increases the surface area-speeds up diffusion). Has no nucleus and is filled with haemoglobin.
Ciliated cells
They are located in your airways. In between these cells are goblet cells, which produce sticky mucus (which traps dirt and bacteria).
Palisade cells
they are specialised for carrying out photosynthesis. They are packed with chloroplasts, have maximum absorption of sunlight and are found near the surface of the leaf.
Chromosome movement
Second stage of the cycle. The chromosomes line up across the centre of the cell. The two identical copies of the cell separate and move to opposite ends of the cell. Now each end have a full set of identical chromosomes, two nuclei form.
Cytokinesis and development of the daughter cells
The third stage is where the cell membrane pinches inwards to separate the two new nuclei, and then pinches off to split the original cell into two genetically identical daughter cells. this process is called cytokinesis. Then each of the daughter cells will then grow independently and the cycle will continue.
Cell cycle
The process of cell growth and division
What are carrier proteins? (Used in active transport)
Special proteins that span across the width of the cell membrane.
A particular molecule that the cell requires binds to a specific carrier protein. Energy is transferred from an energy store to the protein so it can change shape or rotate. Then the carrier protein transports the molecule into the cell.
Percentage change
New result- original result
———————————- x 100
Original result
What affects the rate of diffusion?
Distance, concentration gradient, and surface area.
