cell & osmosis Flashcards
What is the purpose of the cell cycle?
To regulate cell growth and division
What is the primary function of chlorophyll?
To absorb light energy for photosynthesis
What is the primary role of the cytoplasm?
To provide a medium for chemical reactions and support organelles
Fill in the blank: The _______ is a network of membranes that assists in the transport of materials within the cell.
Endoplasmic reticulum
What is the role of the rough endoplasmic reticulum?
To synthesize and process proteins for export or for use in the cell.
What is the primary purpose of cellular respiration?
To convert glucose into usable energy (ATP).
Fill in the blank: The _______ is a sac-like structure that stores materials within the cell.
Vacuole
What is the primary role of chloroplasts in plant cells?
To convert sunlight into chemical energy through photosynthesis.
Multiple choice: Which organelle is responsible for protein modification? A) Ribosome B) Golgi apparatus C) Lysosome D) Nucleus
B) Golgi apparatus
What is the main role of the rough endoplasmic reticulum?
To synthesize proteins destined for secretion or for use in the cell membrane.
what is a living material in a cell called
protoplasm
protoplasm consists of
nucleus, cell surface membrane and cytoplasm
cell surface membrane is also known as
plasma membrane made of lipid molecules, protein and carbohydrates groups
cell wall is made out of
cellulose
cell wall prevents cell from
bursting when too much water enters them
what are ribosomes
sites where proteins are made. uses mRNA molecule to synthesise proteins which are responsible for traits
golgi body
stores and modifies proteins synthesised by the endoplasmic reticulum before secreting them out of the cells thru vesicles
smooth endoplasmic reticulum
synthesise lipids and steroids. detoxification site where harmful substances are converted to non-toxic substances
Cell Surface Membrane
Controls the movement of substances in and out of the cell
Cytoplasm
Contains organelles and is the site of many cellular activities
nucleus
controls all cellular activities and contains chromatin
Vacuoles
Store substances such as water, salts, and sugars
Endoplasmic Reticulum
Transports newly synthesized proteins to the Golgi body
Golgi Body
modifies and packages proteins in vesicles for secretion
cytoplasm is a site for
protein synthesis and cellular respiration
chromatin is made of
dna and proteins
dna and proteins are essential for
division and protein synthesis
in multicellular organisms, there is
division of labour
division of labour is where
specialized cells perform specific functions
Red Blood Cell
Biconcave shape, no nucleus, cytoplasm rich in haemoglobin
Root Hair Cell
Elongated structure, large vacuole, many mitochondria
Xylem Vessel
Long, continuous, hollow tube with a thick cell wall
how does having no nucleus help a red blood cell transport oxygen around the body efficiently?
Without a nucleus, the red blood cell can carry more haemoglobin, a red pigment that binds to oxygen. This allows the red blood cell to carry more oxygen to be transported to other body cells
how does having a biconcave shape help a red blood cell transport oxygen around the body efficiently
The biconcave shape increases the surface area-to-volume ratio of the red blood cell. This allows it to take in and release oxygen more quickly.
how does being flexible and can be bent out of shape help red blood cells transport oxygen more efficiently
The flexibility of a red blood cell allows it to squeeze through capillaries easily.
Muscles need to contract and relax constantly and repeatedly to allow for movement. Hence, muscle cells are one of the most active cells in the body.
Which organelle can be found in greater amount in muscle cells as compared to other types of cells in the body?
has protein fibres that contract and relax for movement, has many mitochondria to release energy for contraction. is elongated, has many nuclei and mitochondria
Which structural feature allows the root hair cell to absorb water and mineral ions from the soil efficiently?
The long and narrow protrusion increases the surface area-to-volume ratio of the root hair cell so that water and mineral ions can be absorbed at a higher rate.
What adaptations do root hair cells have for water absorption?
Root hair cells have elongated structures and numerous mitochondria to increase surface area and provide energy for active transport
What are organelles?
Organelles are specialized structures within a cell that perform distinct functions necessary for cellular operation.
What is the function of the coarse adjustment knob on a microscope?
The coarse adjustment knob is used to bring the specimen into general focus when viewed under low power.
What is the significance of staining cells for microscopy?
Staining cells increases visibility and contrast, allowing for better observation of cellular structures.
What is the process of detoxification in the SER?
Detoxification in the SER involves converting toxic substances into non-toxic forms for safe elimination from the cell.
What is the importance of the fine adjustment knob on a microscope?
The fine adjustment knob is used to achieve a sharper focus on the specimen, enhancing detail visibility.
What is the role of mRNA in protein synthesis?
mRNA carries the genetic code from DNA to ribosomes, where proteins are synthesized.
root hair cell adaptive function
long and narrow root hair to increase the surface area to volume ratio for faster water absorption
muscle cell adaptive function
elongated in shape, contains many nuclei and mitochondria. has numerous mitochondria to release the energy for contraction of the muscle cell
definition of diffusion
net movement of particles from a region (solution) of higher conc to a region of lower conc, down a concentration gradient
concentration gradient is the
difference in conc between two regions
process of diffusion is
slow/passive (low energy needed)
for diffusion, the lid is put on a jar so it
prevent evaporation which affects conc
before diffusing in water, it
dissolves first
______ particles diffuse from
solution around the crystal to the surrounding water
why must the cover slip be lowered at an angle
to remove air bubbles
leaves on an onion does not have any
chloroplasts as no light is present and no mitochondria as photosynthesis does not take place
purpose of mitochondria
aerobic respiration where glucose is oxidised to release energy, this happens when oxygen is present or consumed
chloroplasts are the sites of
photosynthesis and has high concentration of glucose and starch
golgi body’s purpose
chemically modifies subtances like proteins and hormones made by the ER, stores and packages substances in vesicle for secretion out of the cell
function of ribosomes (same func as RER)
synthesise proteins (hormones like insulin and glucagon) in the cell. Attached to the RER. Proteins are either transported out of the cell or lie freely (mobile) in the cytoplasm for its use.
how does the golgi body work
substances made by ER are pinched off from the ER to the golgi body. Vesicle then fuse with golgi body and release their contents into the golgi body. Vesicles containing these modified substances are pinched off from the golgi body. Vesicle fuse with the cell membrane. Contents are released out of the cell.
mitochondria structure
membrane folds
vacuole structure
stack of membranes containing chlorophyll. layers across whole structure
factors that affect rate of diffusion
concentration gradient (difference), diffusion distance, and surface area to volume ratio
define osmosis
net movement of water molecules from a region of higher water potential to a region of lower potential, through a partially permeable membrane
The key points to answering the process of osmosis
1)state the direction of osmosis. 2) Explain the movement (identify region of higher water potential vs lower water potential.) (where is the partially permeable membrane) 3) describe the effect of osmosis (water lvl, firm or soft, mass, length)
how much water potential does a solution have when it is made up of 10% sucrose
90% water
whats the water level of the solution in the Utube at each side (end point)
The side with lower water potential in the beginning will reach the maximum while the side with the higher water potential in the beginning will reach the minimum so that there will be equal water potential at both sides
what is the partially permeable membrane’s purpose during osmosis
so that diffusion of any compounds or substances will not take place
what will happen to the % of sucrose after osmosis
it will decrease as the water potential increases
concentration is a solution made up of
dissolved substances
precaution when measuring mass of dialysis tubing filled with water and solution
dry the water outside the tubing
whats the effect of a cell in a solution with higher water potential
cell contents will enlarge, volume increases. Cell wall is rigid, turgor pressure increases. Cell becomes turgid
what happens to a plant cell in a solution with higher water potential
1.when a plant cell is placed in a solution with higher water potential, the cell sap has lower water potential than solution outside cell. 2. By osmosis, water molecules enter cell thru partially permeable membrane. 3. Cell contents expands, cell becomes turgid. 4. as water molecules enter the cell, the vacuole increases in size, pushing the cytoplasm against the cell wall. The rigid cell wall causes the turgor pressure to build up within the cell
why does the plant cell become turgid when submerged in water
as water molecules enter the cell, the vacuole increases in size, pushing the cytoplasm against the cell wall. The rigid cell wall causes the turgor pressure to build up within the cell
what happens to an animal cell in a solution with higher water potential
water molecules enter by osmosis, cell expands and bursts
what happens to a plant cell in a solution with lower water potential
- when a plant cell is placed in a solution with lower water potential, the cell sap has a higher water potential than solution outside cell 2. by osmosis, water molecules exits the cell thru a partially permeable membrane 3. Cell becomes flaccid 4. cell loses water, vacuole decreases in size. cytoplasm shrinks away from the cell wall (plasmolysis)
lower water potential =
higher % of solute
what happens to an animal cell in a solution with lower water potential
water molecules leave by osmosis, cell shrinks in size
define active transport
energy is used (respiration is involved, many mitochondria, glucose and oxygen) to move the particles of a substance across a membrane against its concentration gradient
active transport can take place with a permeable and
partially permeable membrane
respiration applies to
living cells
describe the process of active transport from the small intestine to the blood capillaries
uptake of glucose by the microvilli of wall cells in the small intestine and from the kidney tubules into the blood capillaries
(root hair) in active transport, higher O2 =
higher mineral salt absorption, AT is more significant than diffusion
active transport in the small intestine during fasting (when low conc of glucose in small intestine)
energy released in walls of small intestine for active transport. ensures that glucose is absorbed into the body cells and not lost by diffusion
to stop osmosis, you need to
remove one region of water potential (drying)
headers for osmosis practical
conc of sucrose solution (mol/dm-3) % original length cm final length cm diff in length cm (state increase or decrease) average change in length cm
