functions of structures

Question 1

Cell membrane

Answer 1

A flexible phospholipid bilayer that controls the entry and exit of substances and encloses the cell; also known as the plasma membrane

Question 2

Cytoplasm and cytosol

Answer 2

The cytoplasm is all of the cell contents (including organelles) between the nuclear membrane and the cell membrane. The cytosol is the semi-liquid (jelly-like) part of the cytoplasm and does not include the organelles. Metabolic activity occurs both in the organelles (in the cytoplasm) and in the cytosol.

Question 3

Endoplasmic reticulum (ER) (rough and smooth)

Answer 3

A network of channels and flattened sacs that extends almost everywhere in the cytoplasm. It transports materials such as proteins throughout this region. It is continuous from the nuclear envelope. There are two types: * smooth ER, which does not have ribosomes attached; it has a unique set of enzymes and carries out many functions, such as the production of membrane phospholipids* rough ER, which does have ribosomes attached and therefore is a site for protein synthesis

Question 4

Lysosomes

Answer 4

A sac of enzymes that can digest (break down) foreign substances, including bacteria, and macromolecules, including lipids, carbohydrates, nucleic acids and proteins

Question 5

Golgi apparatus

Answer 5

A structure of flattened sacs which collect, package, modify and distribute materials such as proteins synthesised in the cell. It:* modifies products of the ER such as proteins* manufactures certain macromolecules* sorts and packages materials into transport vesicle

Question 6

Mitochondria

Answer 6

The site of aerobic cellular respiration, a metabolic process that generates large quantities of a usable form of energy known as ATP (adenosine triphosphate)

Question 7

Nucleus

Answer 7

The structure that contains most of the cell’s DNA. It includes: * a nuclear membrane (envelope), which has pores to allow communication between the nucleus and the rest of the cell* a nucleolus, which is involved in the production of ribosomes* chromatin, which is the loose form of DNA and its proteins, and which only becomes visible as chromosomes during cell division

Question 8

Ribosome

Answer 8

A non-membranous structure that carries out protein synthesis in two locations:* in the cytosol* on the outside of the rough ER

Question 9

Centrosomes and centrioles

Answer 9

Two structures that play a major role in cell division (which is discussed in more detail in Units 3 and 4). The centrosome is located at one end of the cell, close to the nucleus. In many cells microtubules (spindle fibres) grow out from a centrosome. In animal cells, the centrosome has a pair of centrioles

Question 10

Chloroplast
plant strcuture onky bitch

Answer 10

The site of photosynthesis in plant (and algae) cells. Inside these, the light energy from the Sun is converted into chemical energy and stored in carbohydrates

Question 11

Cell wall

Answer 11

A structure made of tough cellulose fibres which protects the plant cell, maintains its shape and prevents excessive uptake of water.Prokaryotes, fungi, and some protists also have cell walls; however, their cell walls are made of different substances from plants

Question 12

Large vacuole

Answer 12

A plant cell (or fungal cell) may have one or several large vacuoles which can store water, nutrients, metabolic wastes and toxins (ready for their removal and also to protect the rest of the cell). In plants, full vacuoles can provide rigidity for the whole organism

Question 13

membrane function

Answer 13

recognition of other cells, the transportation of materials into and out of the cell, the provision of attachment sites for enzymes and hormones, and in nerve cells, the transmission of neural impulses. Both the physical and chemical properties of the cell membrane enable it to control the exchange of materials and messages. Organelle membranes have the same general structure as cell membranes
-selectively permeable>maintaining concentration difference

Question 14

the communication between the cells in tissues and different types of cells through it cell membrane can lead to…

Answer 14

the cell growing, becoming a specialized type of cell, or dying.

Question 15

what do cell have to do in order to create something else sometimes

Answer 15

Depending on its activities, a cell will need to take in certain useful molecules and ions from the external environment and excrete others. For example, a cell that is producing protein needs to take in a variety of amino acids.

Question 16

cholesterol doooooppp in plant and bacteria cells

Answer 16

phytosterol

Question 17

During cell division and vesicle formation, membranes can..

Answer 17

break and reassemble themselves. Additionally, if the cell membrane is punctured, some of the cytoplasm will leak out but the hole will quickly seal

Question 18

cell walls in plant cells prevent..
osmosis

Answer 18

cell to burst when fresh water enters the cell by osmosis

Question 19

vacuole in plant cells
osmosis

Answer 19

large, fluid-filled vacuoles and firm but permeable cell walls that surround the cell membrane. Like the cell membrane, the vacuole membrane is selectively permeable. Plant cell vacuoles contain cell sap that is rich in solutes: it is a solution of high concentration. When a hypotonic solution surrounds a plant cell, water molecules diffuse by osmosis, first into cytosol and then into the vacuole. The vacuole swells, pushing the cytoplasm and cell membrane against the cell wall.

Question 20

function of cyptoplasm

Answer 20

Housing and maintaining an optimal environment for cellular organelles.
Supporting and suspending organelles and cellular molecules.
Serving as the site for many enzymatic reactions and metabolic activities.
Initiating cellular respiration and protein synthesis.
Storing molecules required for cellular processes.

Question 21

function of cytosol

Answer 21

Serving as the medium for intracellular processes.
Being involved in signal transduction between the cell membrane and the nucleus and organelles.
Transporting metabolites from their production site to other parts of the cell.
Playing a role in cytokinesis during cell division.
Supporting other organelles and allowing transport of molecules across the cell.

Question 22

function of nucleus

Answer 22

Control and regulation of cell activities, such as growth and metabolism.
Storage of genetic material (genes) necessary for heredity.
Initiation of cellular reproduction.
Regulation of gene expression.
Protein synthesis with the help of ribosomes.

Question 23

function of mitichondria

Answer 23

Generate energy in the form of adenosine triphosphate (ATP)12345.
Store calcium for cell signaling activities.
Generate heat.
Mediate cell growth and death.

Question 24

function of cell membrane

Answer 24

Acts as a barrier, keeping cell constituents in and unwanted substances out.
Regulates the materials that enter and leave the cell.
Separates and protects the interior of a cell from the outside environment.
Allows certain substances into the cell while keeping others out.
Supports the cell and helps maintain its shape.

Question 25

cell wall

Answer 25

Structural support: The cell wall surrounds the plasma membrane and provides tensile strength.
Protection: It protects against mechanical and osmotic stress.
Turgor pressure: The cell wall allows cells to develop turgor pressure.
Intercellular communication: Small pores called plasmodesmata in the cell wall allow the exchange of nutrients and hormones between cells.

Question 26

vacoules/ vessicles function

Answer 26

Vesicles and vacuoles are membrane-bound sacs that function in storage and transport. Other than the fact that vacuoles are somewhat larger than vesicles, there is a very subtle distinction between them: the membranes of vesicles can fuse with either the plasma membrane or other membrane systems within the cell.

Vacuoles are somewhat larger than vesicles, and the membrane of a vacuole does not fuse with the membranes of other cellular components. Vesicles can fuse with other membranes within the cell system

Question 27

lysosome

Answer 27

Digesting used materials in the cytoplasm, both inside and outside the cell.
Breaking down excess or worn-out cell parts.
Destroying invading viruses and bacteria.
Recycling the cell’s organic material.

Question 28

function of smooth er

Answer 28

Synthesizing and storing lipids, including cholesterol and phospholipids.
Assisting in the production of new cellular membranes.
Playing a role in the synthesis of steroid hormones from cholesterol.
Being involved in lipid metabolism and steroid production.
Functioning in drug detoxification and calcium concentration.

Question 29

function of rough er

Answer 29

Synthesis, folding, and modification of proteins.
Transport of proteins to their targeted destinations.
Quality control of proteins, including identifying misfolded or aberrant proteins.
Rapid signaling to the nucleus when problems in protein synthesis and folding occur.

Question 30

ribosomes

Answer 30

Convert genetic code into protein molecules by reading messenger RNA (mRNA) sequences and determining the order of transfer RNA (tRNA) molecules1.
Produce proteins by linking amino acids together based on the mRNA template

Question 31

golgi apparatus function

Answer 31

Transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations.
Delivering vesicles to different locations throughout the cell.
Tagging vesicles with proteins and sugar molecules for proper targeting.
Serving as the site for the synthesis of complex polysaccharides in plant cells.
Packaging and secreting proteins.

Question 32

glycolipids

Answer 32

Glycolipids are components of cellular membranes comprised of a hydrophobic lipid tail and one or more hydrophilic sugar groups linked by a glycosidic bond.

Maintaining the stability of the cell membrane
Facilitating cellular recognition, which is crucial to the immune response and in the connections that allow cells to connect to one another to form tissues
Providing energy to the cells
Being an essential part of cell membranes
Helping in determining the blood group of an individual

Question 33

high SA: vol ratio

Answer 33

gives faster diffusion rate as the greater surface area is available for particles to transfer

Question 34

the higher the concentration gradient

Answer 34

the higher rate of diffusion

Question 35

need for homeostasis

Answer 35

cell composition needs to remain within narrow limits when faced with changing external conditions. therefore needs to alter inputs and outputs

Question 36

enzyme substrate complex

Answer 36

temporary molecule formed when an enzyme comes into perfect contact with its substrate. Without its substrate an enzyme is a slightly different shape. The substrate causes a conformational change, or shape change, when the substrate enters the active site.

Question 37

substrate

Answer 37

molecule acted upon by an enzyme. A substrate is loaded into the active site of the enzyme, or the place that allows weak bonds to be formed between the two molecules. An enzyme substrate complex is formed, and the forces exerted on the substrate by the enzyme cause it to react, and become the product of the intended reaction.

Question 38

role of inhibitor

Answer 38

prevent building of substaret to enzyme either bi binding preferentially or changing shape of active site so no longer fits reactants. this slows or prevents reactions