B2 - Cells Flashcards
All living organisms are made up of
cells
What are the features that all animal and plant cells have in common
A cell membrane
Cytoplasm
A large nucleus
Mitochondria
What features are in plant cells that animal cells do not have
a cell wall
a large central vacuole
Chloroplasts
What is the function of the cell wall
To give structural support and hold the cell together.
Selectively permeable - controls what substances enter and leave the cell
What is the role of ribosomes
to synthesis proteins
What is the function of the DNA
it contains instructions for making the cell and for all of the cell’s functions
Cytoplasm function
where the cells chemical reactions occur
What is the plant cell wall made up of
cellulose
What is the nucleus of a cell
it is the control center and contains chromosomes to control how a cell grows and works. It also controls cell division
What is the function of the vacoule
the vacuole is used for storage of some materials and contains cell sap. It is also full of water
Mitochondria is the
site of aerobic cellular respiration
What is the Rough endoplasmic reticulum (RER)
it is a membrane bound structure involved with the synthesis of proteins. it is covered in ribosomes and forms near the nucleus
What is a permanent vacuole
it is a fluid filled sac that stores water and can make up to as much as 90% of the cells volume
What is the function of chloroplasts
to absorb sunlight using chlorophyll for the process of photosynthesis
An animal cell contains
Mitochondria, ribosomes, RER, cell membrane, cytoplasm and nucleus
What are specialized cells
cells that have special featured to allow them to carry out their job
what are ciliated cells, their function and adaptations
Function: Ciliated epithelial cells line in the airways and their function is to waft mucus to the back of the throat to be swallowed. They keep the lungs clean
The cells have hair liked structures called cilia
Adaptation: They have mitochondria to provide energy
What are the functions and adaptations of the egg cell
Function: to be fertilized by the sperm cell to become a zygote
It contains half the genetic information needed to form a new zygote and is called a haploid nucleus
Adaptations and features: Has lots of cytoplasms for nutrition for the zygote to grow
The zona pellucida forms when an egg has been fertilized so no more sperm can get in
What are the functions and adaptations of the sperm cell
Function: to fertilize the egg
Adaptations and features: The tail (flagellum) allows the sperm to travel to the egg
The head contains the nucleus which has half the genetic code for the organism
The acrosome has enzymes which help penetrate into the egg
The middle section provides mitochondria for the cell to help travel long distance
What are the functions and adaptations of the red blood cell
Function: To transport oxygen from the lungs to the body
Adaptations and features: They have a biconcave shape allowing for larger surface area and rapid diffusion of oxygen
Contain hemoglobin which carries the oxygen
Small size to fit through capillaries
No nucleus to maximize oxygen absorption
What are the functions and adaptations of the root hair cell
Function: Absorption of minerals and materials
Adaptations and features: They have long projections to increase the surface area that the plant has to absorb water and minerals
No chloroplasts
What are the functions and adaptations of the palisade mesophyll cell
Function: to carry out photosynthesis
Adaptations and features: Pact with chloroplasts
Shaped cylindrically to allow them to be tightly pact at the surface to get as much sunlight
Upper part of the leaf to gain sunlight
Diffusion is the net movement of particles from an area of
high concentration to an area of lower concentration
In diffusion the particles move
randomly because they have kinetic energy
Substances can move in and out of cells across cell membranes via
diffusion
diffusion can allow
Substances to move in and out of cells across cell membranes
What are the factors that affect the rate of diffusion
Concentration gradient (the difference in concentration between two areas): The greater the concentration gradient the faster the diffusion
Temperature: higher temperature means faster diffusion as more particles collide due to kinetic energy
Distance: A longer distance means slower diffusion a shorter distance means faster diffusion
Membrane surface area: The larger the membrane surface area a substance is diffusing through the faster the diffusion
Osmosis is the
diffusion of water across a partially permeable membrane from a dilute solution (high water potential) to a concentrated solution (low water potential).
Investigating osmosis experiment
Osmosis in potatoes
Steps: Cut a potato into discs and measure their mass
Put discs in different concentrations of salt or sugars
after 30 minutes measure the mass of each disc again
If the mass of the disc has decreased it has lost water by osmosis
If the disc has increased it has gained water by osmosis
What is the process of a plant being plasmolysed
If a plant loses a large amount of its water due to osmosis the cell volume decreases so that the cell membrane pulls away from the cell wall. It causes cell damage
What does it mean if a plant cell is turgid
Water comes into the plant cell via osmosis and is swollen.
Why does an animal cell burst but not a plant cell from osmosis
Because plant cells have inelastic cell walls in which the swollen cell exerts turgor pressure onto the cell wall. Animal cells don’t have cell walls and burst because the cell membrane can only handle enough pressure.
when water moves out of the cell it becomes
droopy or flaccid
When water moves into the cell the cell
exerts turgor pressure on the cell wall
When you place an animal cell into a solution of low water potential it loses water by osmosis and becomes
crenated
