B1: Cell Biology Flashcards
What is the function of the cell membrane?
Hold the cell tg, controlling what enters and leaves cell
What is the function of the cytoplasm?
Jelly like substance, chemical reactions happens, surrounds subcellur structures
What is the DNA?
Genetic material ,controls activities of the cell
What is the function of the ribosomes?
Site of protein syntheses
What are eukaryotic cells?
Plant and animal cells. Cellemebran, cytoplasm, ribosomes, DNA enclosed in a nucleus, 10-100 micrometers
Structure of a typical animal cell?
Nucleus w DNA, , cytoplasm, ribosomes , cell membranes, mitochondria
Structure of a typical plant cell?
Cell wall (cellulose), permanent vacuole, ribosomes, chloroplasts,
What is a prokaryotic cell?
Bacterial cells, no nucleus, DNA is a single loop in the cytoplasm less than 1 micrometre
Structure of a prokaryotic cell?
Cell membrane, circular loop of DNA in cytoplasm, plasmid (DNA), robosomes, cell wall (peptidoglycan)
Function of mitochondria?
Aerobic respiration, high rates of metabolism have more mitochondria
Function of the nucleus?
Contains genetic material , controls cells activities
Function of cell wall?
Defines shape, gives structure,
Function of chloroplasts?
Contains chlorophyll, site of photosynthesis
Function of vacuole?
Cell sap ( sugars and slats in water), storage, supports shape
What is a specialised cell?
Structure that aids it’s specific function
What is the function of a nerve cell?
Conducts electrical impulses
How is a nerve cell adapted to its function?
LONG- can conduct impulses between different areas of the body
DENDRITES: (extensions of cytoplasm, can communicate w other nerve cells
FATTY SHESTH: covers axon, speeds up transmissions
What is the function of a muscle cell?
Contraction for movements
How is a muscle cell adapted to its function?
MANY MITOCHONDRIA: release energy for contraction
PROTEIN FILAMENTS: can slide over each other for contraction
WHAT IS THE FUNCTION OF A SPERM CELL?
Transfers genetic material to an egg cell for fertilisation
How is a sperm cell adapted to its function?
MITOCHONDRIA: release energy for the tail
TAIL ROTATES: helps propelling to the egg
ACROSOME CONTAINS DIGESTIVE ENZYMES: can break down outer layer of cell
What is the function of a root hair cell?
Absorption of water and mineral from soil
How is a root hair cell adapted for its function?
ROOT HAIRS: increase surface area , faster osmosis
THINNER WALLS: shorter diffusion distance
MITOCHONDRIA: energy for active transport of minerals
What is the function of a xylem cell?
Transport f water and dissolved ions in a plant
How is a xylem cell adapted for its function?
NO WALLS ON THE TOP OR BOTTOM: forms a continuous tube for water is drawn up
NO ORGANELLES: free passage of water
OUTER WALLA THICKENED W LIGNIN: strengthens tubes
What is the unction of a phloem cell?
Transport of dissolved sugars and amino acids up and down the plant
How is a phloem cell adapted to its function?
HOLES IN THE TOP AND BOTTOM WALLS TO FROM SIEVE PLATE: allows sugars and amino acids to flow easily
FEW SUBCELLULAR STRUCTURES
What is cell differentiation?
Process where a cell becomes specialised
When do most cells differentiate in animal cells?
Early stages of development, animal cells lose their ability to differentiate after they have become specialised
Where are stem cells in an animal?
ADULT: bone marrow
EMBRYONC: embryo
Where are stem cells in a plant?
Meristems
How are electron microscopes better than light?
Better resolution, better magnification
What is the magnification equation?
Image size/ actual size
How many micrometers in in a millimetre?
1000
What are chromosomes?
Coils of DNA in the nucleus
What is a gene?
A short section of DNS that codes for a protein the controls a characteristic
What is the cell cycle?
The series’s of steps a cell has to go through in order to divide
What is stage 1 of the cell cycle?
Interphase: the cell grows and DNA is replicated
What is stage 2 of the cell cycle?
Mitosis: chromosomes line up across the equator , each chromatic on one side, chromatids are separated and pulled to opposite sides, a new nucleus forms around these chromatids
What is stage 3 of the cell cycle?
Cytokinesis: two identical daughter cells are formed as the cell membrane and cytoplasm pinches
What is therapeutic cloning?
Embryonic stem cells are harvested with the same genes as a patient, so they won’t be rejected
What are the benefits of research with stem cells?
Can be used to replace body parts
Unwanted embryos can be used instead of being discarded
What are negatives of stem cell research?
Destruction of embryo
Religious or ethical beliefs
How do you calculate the amount of time in a a stage of the cell cycle from a table with the observation of the amount of cells in that stage?
Length of time in stage = (observed no. Of cells) / (total number of cells observed) x total length of cell cycle
What is diffusion?
Net movement of particles from an are of high concentration to an area of low concentration
What are the factors that affect diffusion rates?
Concentration gradient, temp., surface area
What is osmosis?
Movement of water from a less concentrated solution to a more concentrated one through a a partially permeable embrace
Does osmosis use energy?
No: moves down the concentration gradient
When a cell is places into a solution, it can become isotonic? What does this mean?
When the concentration of sugar in the external solution is the same as the internal
When a cell is places into a solution, it can become hypertonic? What does this mean?
Is the concentration of sugar is higher in the external solution, so water moves out of the cell
When a cell is places into a solution, it can become hypotonic? What does this mean?
When the concentration of sugar is lower in the external solution, so water moves into the cell
What happens to a hypotonic animal cell?
It’s can burts
What happens to a hypertonic animal cell?
It can shrivel
What happens to a hypertonic plant cell?
The cell wall will move away from the cell (plasmolysis)
What happens to a hypotonic plant cell?
The plant cell becomes turgid
What is active transport?
The movement of particles from an area of a low concentration to an area of higher
Does active transport require energy?
Yes, against the gradient
Examples of active transport?
Root hairs of a plant: mineral ions
In the gut: sugar molecules
Rp : potato osmosis thing😭🙏
