Biology - cells and cell processes Flashcards
What are the parts of an animal cell?
cytoplasm, ribosomes, Rough ER, smooth ER, nucleus, cell membrane, Golgi complex, mitochondria, lysosome
What are the parts of a plant cell?
Rough ER, smooth ER, Golgi complex, chloroplast, mitochondria, nucleus, cell wall, permanent vacuoles, cell membrane, ribosomes
What is a cell wall?
provides structural support, protection, and helps maintain the cell’s shape
What is a nucleus?
The control centre of the cell that contains DNA and regulates gene expression
What is a cytoplasm?
The jelly-like substance inside the cell where organelles float and most cellular processes occur
What is a chloroplast?
Organelles in plant cells that contain chlorophyll and carry out photosynthesis to produce food for the plant.
What is mitochondria?
The powerhouse of the cell, where energy (ATP) is produced through respiration
What is a vacuoles?
Large storage sacs in cells that hold water, nutrients, and waste products, helping maintain cell shape and balance
What is a cell membrane?
The outer boundary of the cell that controls what enters and leaves the cell
What is a ribosome?
Tiny structures that make proteins
What is a golgi complex?
A series of membranes that modify, package, and distribute proteins and lipids
What is a lysosome?
Small organelles containing enzymes that break down waste materials and cellular debris
What is a rough ER?
A network of membranes with ribosomes attached
What is a smooth ER?
A network of membranes without ribosomes
What are 4 differences of plant and animal cells?
- cells walls are in plant cells but not animal cells
- chloroplast is present in plant cells for photosynthesis but not animal cells
- there are large central vacuole in plant cells, but small or absent in animal cells.
- the shape: Plant cells are generally rectangular, while animal cells are more rounded.
Describe ciliated cell
Its function is to move dust and
microorganisms away from the
lungs.
Describe root hair cells
Its function is to absorb water and
minerals from the soil.
Describe xylem vessals
Its function is to transport water and dissolved minerals from the roots to the rest of the plant
Describe palisade mesophyll cells
Its function is to carry out
photosynthesis to make glucose
for the plant.
Describe nerve cells
Its function is to carry nerve
impulses around the body.
Describe red blood cells
Its function is to transport oxygen
around the body.
Describe sperm
Its function is to fertilise an egg cell.
Describe egg cell
Its function is to be fertilised by a
sperm cell.
Define cell and give an example
smallest unit that can carry out life’s activities e.g blood and nerve cells
define tissue and give an example
group of cells with similar structures e.g muscle and nervous tissues
define organ and give an example
group of tissues working together to perform specific functions e.g. stomach, and heart
define organ system and give and exmaple
group of organs with related functions working together to perform bodily functions e.g. digestive system, and immune system
What are the six organ levels?
- Chemical level
- Cellular level
- Tissue level
- Organ level
- System level
- Organismal level
What is the chemical level?
Atoms bond to form molecules with 3D structures
What is the cellular level?
Variety of molecules combine to form fluid and organelles ( e.g smooth muscle cell )
What is the tissue level?
Community of similar cells form a body tissue (e.g smooth muscle tissue)
What is the organ level?
two or more different tissues combine to form an organ
What is the system level?
two or more organs work closely together to perform the functions of body system
What is the organismal level?
Many organs work together to perform functions of an independent organisms
What is the order to convert units
cm, mm, µm, nm ( x10 x 1000 x 1000, divide on the bottom ) ( 10, 1000, 1000)
What are in cells?
Organelles
What is the triangle for calculating magnification?
I (size of image) on top, M (magnification) and A ( actual / real size of object)
What is the diffusion theory?
the net movement of molecules using their own kinetic energy from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement.
they are substances that move into and out of cells by diffusion
How does surface area affect diffusion?
More space allows more particles to move across, speeding up the process.
How does temperature affect diffusion?
Particles move faster at higher temperatures, leading to quicker spreading.
How does concentration gradient affect diffusion?
Particles move from areas of high concentration to low concentration, so a bigger difference leads to faster movement
How does distance affect diffusion?
The closer the two areas are, the faster particles can move between them.
Define Osmosis
The diffusion of water molecules from a region of their higher water potential (dilute) to a region of their lower water potential (concentrated), through a partially permeable membrane.
When writing the answer for magnification, what goes at the start?
x
e.g x 1000
What does osmosis mean in cells?
In order to maintain their shape, cells need to regulate how much water comes in and out of them
What does plasmolysis do in plants?
- The water diffuses out of the cell to equalize the solute concentrations,
- the loss of water volume in cytoplasm causes the cell membrane peel away from cell wall
- plant cell shrink and crumples
Why is turgor pressure so important to plants?
- provides structural integrity to each cell and to the tissue as a whole
- Turgor in root cells builds up root pressure which helps to absorb more water
What happens when put in solution with same water potential?
no overall change
animal cell is called normal
plant is called flaccid
What happens when put in solution with lower water potential?
Cells lose water
animal is called shrivelled
plant is called plasmolysed
What happens when put in solution with higher water potential?
cells gain water
animal is called lysis
plant is called turgid
hypertonic meaning
This solution is concentrated
(contains very little water) said to be plasmolysed.
hypotonic meaning
This solution is dilute (contains a lot of water). said to be turgid
isotnic meaning
There is no difference in concentration and the
movement of water remains constant. Said to be flaccid.
What is osmosis a form of?
Diffusion but only applies to water
How do the water particles move in osmosis?
From low concentration to high concentration
Why is osmosis important?
- it regulates the amount of water inside plant and animal cells.
- Water is an important solvent
- It offers support to the cell
What happens to animal cells in the same water potential?
- no change to cell
- Isotonic
- Normal
What happens to animal cells in the high water potential?
- water will enter the cell moving down the concentration gradient.
- Hypotonic
- will swell and lyse (burst)
What happens to animal cells in the low water potential?
- water will leave the cell moving down the concentration gradient.
- hypertonic
-cells will shrivel
What happens to plant and animal cells in a hypotonic solution?
Both: Water potential is higher outside the cell. Water moves into the cell.
Plant:Cell becomes turgid (swollen but doesn’t burst).Strong cell wall prevents bursting.
Animal:Cell swells and may burst (lysis). No cell wall to prevent bursting.
What is a turgid cell?
Full of water.
Occurs in hypotonic solution.
Water enters the cell.
Cell is firm due to pressure against cell wall.
What happens to plant cells in an isotonic solution?
Both: Water potential is the same inside and outside. Water moves in and out equally. No net gain or loss of water.
Plant: Cell becomes flaccid (not firm).
Animal: Cell stays the same size and shape. Ideal condition for animal cells. Normal and healthy.
What is a flaccid cell?
Not firm, slightly soft.
Water moves in and out equally.
Occurs in isotonic solution.
What happens to plant cells in a hypertonic solution?
Both:Water potential is higher inside the cell. Water moves out of the cell.
Plant: Cell becomes plasmolysed (shrinks). Membrane pulls away from cell wall.
Animal: Cell shrinks and becomes crenated.
What is a plasmolysed cell?
Loses water and shrinks.
Occurs in hypertonic solution.
Membrane pulls away from the wall.
What are plants supported by?
plants are supported by the turgor pressure within cells due to the inelastic cell wall
What is lysis in animal cells?
Cell bursts due to too much water entering.
Happens in a hypotonic solution.
No cell wall = no protection from swelling.
What is a crenated animal cell?
Cell becomes shrunken and wrinkled.
Happens in a hypertonic solution.
Water leaves the cell.
Describe active transport:
the movement of ions in or out of a cell through the cell membrane, from a region of their lower concentration to a region of their higher concentration against a concentration gradient, using energy released during respiration, using. ion uptake by root hairs and uptake of glucose by epithelial cells of villi and kidney tubules as examples
What do protein molecules do?
protein molecules are needed to move large or charged particles across the membrane
What does a normal plant look like and what can you tell about the soil they are planted in?
A normal plant means turgid or normal plants cells and either isotonic or hypotonic
What does a shrivelled plant look like and what can you tell about the soil they are planted in?
Means plasmolyse and hypertonic soil
Why do you think plants cells need to be flaccid or turgid?
So their leaves are upturned to get the most amount of sunlight that can to be used in photosynthesis
What are ways that transport occurs across a cell membrane?
Diffusion, and active transport
What is an example of active transport in animal cells?
the movement of nutrients from the gut into the blood
What is an example of transport in plant cells?
absorb minerals from the soil
What are two processes in organisms that use water as a solvent?
- Digestion
- Transport of substances through bloodstream or sap
What does active transport need that diffusion doesn’t
Energy
What is Facilitated Diffusion?
Same as diffusion but uses channel/carrier proteins for larger or charged particles
