cell composition and science M1V1

Question 1

what is a cell

Answer 1

• the smallest possible living, self containing unit
• organelles IN cytosol SURROUNDED by a membrane
• carries out all of life’s functions
• they are tiny, and we have many

Question 2

what are cells measured in

Answer 2

microns (1/1000th of a millimetre)

Question 3

what are molecules measured in

Answer 3

nanometres (1/100th of a mircron)

Question 4

light microscope

Answer 4

• used to see whole cells/ live tissue in colour

Question 5

transmission electron microscope

Answer 5

• bigger magnification

- used to see intracellular organelles and membranes / dead tissue in black and white

Question 6

scanning electrons microscope

Answer 6

like TEM but 3D

Question 7

what do all cells have in common

Answer 7

• plasma membrane
• chromosomes (DNA)
• Cytosol
• ribosomes

Question 8

prokaryotes

Answer 8

• cells that dont have membrane bound nuclei and organelles

- include the domain bacteria

Question 9

eukaryotes

Answer 9

• cells that have membrane bound their nuclei and organelles

- includes the domain Eukarya (which includes many Kingdoms, including animals and plants)

Question 10

germ theory

Answer 10

• many diseases caused by microorganisms in the body
• straight neck flash caused sterile broth to become contaminated
• crooked neck flask (ie no bacteria could get into the broth) caused broth to remain sterile

Question 11

pasteurs challenge and fermentation - he tested four theories

Answer 11

he tested four theories

1. fermentation occurred spontaneously - he sealed a flask of sterile grape juice, and it didn’t ferment (rejected)
2. air fermented the juice - had a curved neck to allow air access but stop microbes, no fermentation (rejected)
3. bacteria ferment into alcohol - innoculated with bacteria and sealed, but fermentation into acid occurs (change)
4. yeasts ferment it into alcohol - innoculated with yeast, sealed, alcohol produced (accepted)

Question 12

kochs postulates - 4 criteria

Answer 12

1. organism present in every case of disease
2. organism must be isolated from host with disease and grown in pure culture
3. specific disease reproduced when pure culture of that organism is put into a healthy host
4. organism must be recoverable from said host after the disease develops

all 4 of these must be met to prove that disease is caused by a particular microorganism

Question 13

cell composition

Answer 13

• the human body is mostly oxygen, with carbon, hydrogen and nitrogen abundant as well
• these 4 elements combine to make the simple building blocks essential to all functions of cells and the body

Question 14

what are the important parts that are key to a cells role

Answer 14

macromolecules, they are bio-polymers formed by lots of repeating units

Question 15

what are the building block (repeating units) for these bio-molecules

1. Protein
2. Deoxyribonucleic acid (DNA)
3. Ribonucleic acid (RNA)
4. Polysaccharide (glycogen)
5. Lipids

Answer 15

1. amino acids
2. deoxyriboncleotides
3. Ribonucleotides
4. Monosaccharides (glucose)
5. fatty acids, glycerol

Question 16

carbohydrates

Answer 16

help in cell recognition, energy and structure

• Monosaccharides (building blocks) form disaccharides (2), oligosaccharides ( a few) and polysaccharides (many) which link together to form carbohydrates

Question 17

glucose

Answer 17

is a monosaccharide, and can exist in alpha and beta forms

Question 18

lipids

Answer 18

• NOT polymers but come in lots of different forms

- Hydrophobic (repels water)

Question 19

function of lipids

Answer 19

• Membrane structure (cholesterol and phospholipids)
• Regulation
• Energy

Question 20

nucleic acids

Answer 20

• A ribose sugar combines with a phosphate and a base to form a nucleotide
• bases include thymine, adenine, cytosine, guanine and uracil
• nucleic acids are polymers of nucleotides
• they include DNA and RNA
• Informational molecules

Question 21

proteins

Answer 21

• polymers of the 20 different amino acids
• 100,000 unique proteins in the body
• genes give rise to proteins (covered later) - can give rise to just one or several

Question 22

function of protein

Answer 22

they perform almost every function there is

Question 23

how are proteins structured

Answer 23

proteins are formed by amino acids combine a long line called a peptide chain and then they form into a structure called a protein