How do Cells do What They do?

Question 1

What is a cell

Answer 1

the fundamental structural and functional unit of all living things

Question 2

What are the functional characteristics of cells?

Answer 2

cell metabolism (chemical reactions): production of energy. oxygen and glucose are used to create proteins and hormones

synthesis of molecules: cells ability to create RNA and proteins

Communication: cell communication with surroundings and each other by sending and receiving electrical signals

Reproduction / inheritance: the ability to divide and reproduce, passing genetic material to daughter cells

Question 3

What are the key components of the cell?

Answer 3

plasma membrane
cytoplasm
nucleus

Question 4

Cytoplasm

Answer 4

FUNCTION: Fluid material outside the nucleus but within plasma membrane

STRUCTURE:
cytosol: fluid portion with ions and proteins
cytoplasmic inclusions: aggregates of chemicals
cytoskeleton: supports the cell and its organelles and aids in cell shape. contains microtubules, microfilaments and intermediate filaments

Question 5

Nucleus

Answer 5

FUNCTION: Control centre of the cell that houses DNA (carries code for structural and functional traits)

STRUCTURE:
Nuclear envelope: bilayer surrounding nucleus
Nucleolus: produces ribosomes
Chromatic: long strand of DNA and proteins that condense into chromosomes during cell division

Question 6

Ribosomes

Answer 6

FUNCTION: The site of protein synthesis where amino acids are assembled into proteins

STRUCTURE:
2 sub units (large and small)
can be free floating in cytoplasm or attached to endoplasmic reticulum

Question 7

plasma membrane (cell membrane)

Answer 7

FUNCTION: security gate/ perimeter around the cell and supports the content of the cell. regulates what enters and exits and has receptors for cell communication.

STRUCTURE: phospholipid bilayer for flexibility.
Lipid bilayer: polar heads (hydrophilic) and non-polar tails (hydrophobic)
contains proteins (45-50%), carbohydrates (4-8%), and a fluid mosaic model structure.
Glycocalyx is the outer surface of the cell membrane

Question 8

endoplasmic reticulum (ER)

Answer 8

FUNCTION: A network of interconnected sacs and tubules.
- rough ER: synthesises and modifies proteins
- smooth ER synthesises lipids, steroids and carbohydrates, breaks down harmful chemicals and glycogen

STRUCTURE: rough ER is studded with ribosomes while smooth ER has no ribosomes

Question 9

golgi apparatus

Answer 9

FUNCTION: modifies, packages and prepares proteins and lipids made by ER for distribution

STRUCTURE: stacks of flattened membranes

Question 10

lysosomes

Answer 10

FUNCTION: contains enzymes that digest waste products (molecules) not needed anymore by the cell.
including nucleic acids, proteins and lipids

STRUCTURE: membrane bound vesicles formed by golgi apparatus

Question 11

mitochondria

Answer 11

FUNCTION: ‘power house of the cell’, breaks down food molecules into ATP

STRUCTURE: Outer membrane, Inter-membrane, inner membrane and matrix.

Contains genetic material and can reproduce on its own

Question 12

centrioles

Answer 12

FUNCTION: cell division

STRUCTURE: barrel shaped organelles arranged at right angles, made of microtubules. 2 centrioles are found in the centrosome

Question 13

cilia

Answer 13

FUNCTION: movement of substances across the surface of cells

STRUCTURE: whip like, motile cellular extensions which project from outer surfaces of certain cells

Question 14

flagella

Answer 14

FUNCTION: motility of the entire cell

STRUCTURE: longer than cilia, only found on sperm cells

Question 15

microvilli

Answer 15

FUNCTION: increase surface area of cell, enhancing ability to absorb materials

STRUCTURE: extensions of plasma membrane that do not move

Question 16

What is histology?

Answer 16

The study of tissues. aims to understand micro anatomy of cells, tissues and organs

Question 17

What is haematoxilyn and eosin? (H&E)

Answer 17

Most common type of stain. stains nuclei and cytoplasm.

Haematoxilyn stains nuclei purple
Eosin stains cytoplasm pink

Question 18

What is the order of preparation of tissue?

Answer 18

1. remove tissue from the body through a biopsy or autopsy
2. fixation of tissue (para-formaldehyde)
3. embed tissue (wax)
4. slice the tissue and put onto glass slide
5. staining and viewing the tissue with microscope

Question 19

What are the primary tissues? what do they do?

Answer 19

Epithelial - covers
connective - supports
muscle - movement
nervous - control