Cells Flashcards
What organelles do animal cells contain but plant cells dont
Lysosome
What organelles do both plant and animal cells share
Nucleus Cytoplasm Cell membrane Mitochondria Golgi Cytoskeleton Nucleolus Ribosome
What organelles do only plant cells contain but animal cells dont
Cell wall
Permanent Vacuole
Chloroplasts
Nucleus
Control centre of the cell, contains genetic information
Cytoplasm
Liquid gel in which most of the chemical reactions take place
Cell membrane
Semi-permeable controls movement of material in and out of cell
Cell wall
Supports and protects plant cell
Mitochondrion
The ‘powerhouse’ of the cell (produces ATP by respiration)
Ribosome
Production of proteins
Chloroplast
Uses energy to make food by photosynthesis
Permanent vacuole
Stores food water and waste in plants
Lysosome
Special type of vacuole that breaks down old cell parts and large molecules
ER
Transport of chemicals and proteins within a cell
Golgi
Modifies proteins to make them functional; and transports proteins within cells
Cytoskeleton
Support structure within cells (skeleton); made of proteins
Organ
Collection of tissues that perform a specific function within an organism
Eg liver
Organism
A living being
Eg mouse
Organelle
A functional structure within a cell
Eg nucleus
Organ system
Collection of organs that perform a specific function within an organism
Eg digestive system
Tissue
Collection of connected cells that perform a similar function within an organism
Eg muscle
Cell
The structural unit of an organism may exist as an independent life
Eg blood cell
Name a specialised cell
Sperm cell
Fertilisation of egg
With tail for movement, many mitochondria, genetic info
Name a specialised cell
White blood cell
Destroy pathogens
Some produce antibodies, some have flexible cytoskeletons so they can change shape quickly to engulf bacteria
Name a specialised plant cell
Palisade cell
Photosynthesis
Lots of chloroplasts, tightly packed, elongated
Name a specialised plant cell
Root hair cell
Uptake of water and material
Have root hairs (increase SA), large permanent vacuole, close to xylem (water transport)
Diffusion
- the movement of gases or dissolved molecules from an area with a high concentration to an area with low concentration until an equilibrium is reached
- the movement of molecules down a concentration gradient
- molecules (gas or dissolved) move around randomly due to kinetic energy
- when an equilibrium is reached there is no net movement
Diffusion across membranes
Cell membranes are selectively permeable allowing O2 and CO2 in, mostly letting glucose amino acids and iron in, but not letting larger molecules like starch and protein
Diffusion: Concentration gradient
The higher the concentration gradient, the faster the rate of diffusion
Diffusion: diffusion distance
The smaller the diffusion distance the faster the rate of diffusion
Diffusion: SA
The larger the SA the faster the rate of diffusion
Diffusion: temperature
The higher the temperature the greater the rate of diffusion as the molecules have more kinetic energy
How does the size affect the rate of diffusion
Organism larger SA/V gets smaller therefore diffusion takes longer
Define SA/V
The amount of surface area per unit of volume
When is a large SA/V good
- gets rid of waste products quicker eg CO2
- lose heat easily (for hot climates)
When is a small SA/V ratio good
Diffusion of useful molecules (eg O2) occurs quicker
How can an organism increase its SA/V
Decrease its volume/increase surface area
Define osmosis
The movement if water molecules from an area of high concentration to an area of low concentration across selectively permeable membranes
What happens when a plant cell is inside a solution with a very high sugar concentration
Water leaves the cell via osmosis therefore the cytoplasm and vacuole shrink and the cell becomes ‘plasmolysed’
What happens when an animal cell is put inside a solution with a very high sugar concentration
Water leaves the cell via osmosis therefore the cell shrinks and becomes flaccid
What happens when a plant cell is put inside a solution with a very low sugar concentration
Water enters the cell via osmosis therefore the cell swells and might burst
What happens when an animal cell is put in inside a solution with a very low sugar concentration
Water enters the cell via osmosis therefore the cell swells and might burst
Osmosis summary:
High solute outside
Same solute outside
Low solute outside
Shrivelled
Normal
Burst (lysed)
Isotonic
Same concentration in osmosis
ie flaccid
Hypotonic
Lower solute concentration outside the cell (high water concentration outside the cell)
ie turgid
Hypertonic
Higher solute concentration outside the cell ( lower water concentration outside the cell)
ie plasmolyzed
Facilitated diffusion
The movement of a molecule from an area of high concentration to an area of lower concentration with the help of a protein channel or carrier (glucose, amino acids, ions)
Passive transport
The movement of molecules through cell membranes without the use of energy by the cell (diffusion, facilitated diffusion, osmosis)
Active transport across membranes
The movement of molecules through cell membranes against a concentration gradient at the cost of energy and with the help of a carrier protein (the energy for active transport comes from respiration and is stored in the form of ATP)
Carrier protein
Proteins that are involved in the transportation of ions, molecules or macromolecules across a cell membrane
Channel protein
Line water filled pores in the membrane so that water soluble molecules can easily pass through
Label an animal cell
Bxnd
Label a plant cell
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