1.1.1 Biological Molecules/1.1.2 Cell Biology Flashcards
What are 2 functions of Carbohydrates?
- Act as a source of energy in plants and animals
- eg. sugars, starch, glycogen - To play a structure role in plant cell walls
- eg. cellulose
define alpha glucose
H on top and OH on bottom
define beta glucose
OH on top H on bottom
What is the monomer and polymer for Carbohydrates
Monomer - monsaccharide
Polymer - Polysaccharide
what is the monomer and polymer for proteins
monomer - amino acids
polymer - polypeptide
what is the monomer and polymer for Nucleic acids?
monomer - nucleotide
polymer - DNA
define monomer
one of many small molecules that combine to form a larger one
define polymer
large molecule made up of small repeating units
what is the general formula for monosaccharides?
(CH2O)n
what is a condensation reaction?
the elimination of water allows monosaccharides to bond together
what is a hydrolysis reaction?
breaking the chemical bond by the addition of a water molecule
what are the 2 substances in starch?
amylose and amylopectin
what type of glucose is starch
Alpha - that forms amylose and amylopectin
what linkages does Starch form?
Amylose - 1,4 glycosidic
Amylopectin - 1,6 glycosidic
Does starch have branching?
amylose - no: straight chains
amylopectin - yes: some branchin
what type of glucose is cellulose?
Beta
what type of linkages does cellulose have?
1,4 glycosidic
1,6 glycosidic
(flips 180 degrees with each molecule)
does cellulose have branching?
- no: straight chain that rotates 180 degrees
- forms microfibrils
define primary structure of protein
a sequence of amino acids which form a polypeptide chain - linked by peptide bonds
define secondary structure of protein
alpha helix (swirl) and beta pleated sheet (zig-zag)
define tertiary structure of protein
tertiary: the folding of alpha helix to form specific 3D shapes
R groups interact to form bonds:
- Hydrogen bond (OH-H)
- Ionic bond (+ and - charges)
- disulfide bridges (S-S)
- Hydrophobic interactions (clustering of hydrophobic groups away from water)
define quaternary structure of proteins
Two or more polypeptide chains in tertiary form combine to form complexes joined by bonds similar to those in tertiary structure
Which elements make up protein?
C,H,O,N
what are lipids made up of?
C,H,O, plus phosphorous as phosphate in phospholipids
what is the structure of a phospholipid?
glycerol head, phosphate group and 2 fatty acids
What is the structure of a triglyceride?
3 fatty acids and a glycerol head
what bond does a carbohydrate form?
glycosidic
what bond does a protein form?
peptide
what bond does a lipid form?
ester
starch, glycogen and cellulose are all…
polysaccharides
what are the features of a eukaryotic cell?
- DNA in a nucleus
- membrane-bound organelles
- do not contain plasmids
- larger: 80s ribosomes
what are the features of a prokaryotic cell?
- free DNA not enclosed in a nuclear membrane
- no organelles
- contain some plasmids
- smaller: 70s ribosomes
- cell wall made of murein
what are fungal cell walls made of?
chitin
do animal cells have cell walls?
no
what is the benefit of having a large SA:V ratio?
Increases the rate of diffusion
what is the main function of mitochondria?
site where ATP is produced during respiration
what is the structure of a Mitochondria?
- two membranes separated by a fluid filled space
- Inner membrane is folded to form cristae
- Central part is the matrix
what is the function of a choloroplast?
- site of photosynthesis
- light energy is used to derive carbohydrate molecules from carbon dioxide
what is the structure of chloroplasts?
- 2 membranes separated by a fluid filled space
- inner membrane is continuous with a network of thylakoids
- a stack of thylakoids is called a granum
- chlorophyll molecules are present on these membranes
What is the function of the Rough Endoplasmic Reticulum (RER)?
Synthesises and transports proteins made on attached ribosomes
what is the function of Smooth Endoplasmic Reticulum?
Involved in making carbs, lipids and steroids
what is the structure of the Endoplasmic Reticulum?
Consists of flattened membrane-bound sacs (cisternae), which are continuous, with the outer membrane
- Rough ER - Ribosomes
- Smooth ER - no ribosomes
what is the function of the Golgi Body?
- receives proteins from the ER
- modifies them e.g. adds sugar
- packages proteins into vesicles to be transported inside or outside the cell
what is the structure of the Golgi Body?
Stack of membrane-bound flattened sacs
what is the function of ribosomes?
site of protein synthesis which acts as an assembly line to use mRNA to assemble proteins
what is the structure of ribosomes?
- very small organelles in the cytoplasm and bound to rough ER
- consists of 2 subunits
what is the function of the nucleus (including nuclear envelope and pore)
- contains genetic material
- contains instructions for making proteins
what is the structure of the Nucleus?
- surrounded by nuclear envelope
- has nuclear pores
what is the function of a lysosome?
- contains digestive enzymes which break down materials
what is the structure of a lysosome?
spherical sacs surrounded by a single membrane
what is the function of a vacuole?
- storing water in plant
- helping maintain turgor pressure within a cell
what is the structure of a vacuole?
- surrounded by a tonoplast
- filled with cell sap
what is the function of a cell membrane?
- selectively permeable to ions and organic molecules and regulates the movement of substances in and out of cells
what is the structure of a cell membrane?
- composed of a phospholipid bilayer with embedded proteins
what is the function of the cell wall?
- provides rigidity, tensile strength, structural support
what is the structure of a cell wall?
composed of cellulose in plant cells. Chitin in fungi. Peptidoglycan in bacteria
Recall the Fluid Mosaic Model
