Lecture 4 Flashcards
Function of cellulose
Strengthens plant cell walls
What is the function of monosaccharides and disaccharides?
Fuel; carbon source that can be converted to other molecules or combined into polymers
What is the function of starch?
Stores glucose for energy
What is the function of glycogen?
Stores glucose for energy
What are the types of lipids?
- triacylglycerols (fats/oils) glycerol + 2 fatty acids
- phospholipids (phosphate group + 2 fatty acids)
- steroids (4 fused rings with attached chemical groups)
- fat soluble vitamins
What is the function of triacylglycerols
Important energy source (more than glucose because of long C chains as opposed to 6 carbons)
What is the function of phospholipids?
Lipid bilayer of membranes, structural function
Long fatty acid chain
What is the function of steroids?
- components of cell membranes (cholesterol) structural function
- signalling molecules that travel through the body (hormones) and regulatory function
What is the function of structural proteins?
Provide structural support
What is the function of regulatory proteins (peptide hormones)
Coordinate organismal responses
Function of motor proteins
Function in cell movement
Function of transport proteins
Transport substances
What is the function of protective proteins
Fight infections (immune system)
What is the function of storage proteins
Store amino acids
What is the function of defence proteins?
Protect against disease
What is the function of DNA?
Stores hereditary information
What is the function of RNA
Various functions during gene expression, including carrying instructions from DNA to ribosomes
What are the atomic constituents of the human body (of biological macromolecules)
- oxygen
- carbon
- hydrogen
- nitrogen
What are the molecular building blocks?
- amino acids
- nucleobases
- simple carbohydrates
- lipids
What do amino acids go through polymerisation to form?
Proteins (macromolecule = polymer)
Nucleobases go through polymerisation to form?
DNA and RNA (nucleic acid) (macromolecule = polymer)
What do simple carbohydrates go through polymerisation to form?
Complex carbohydrates (macromolecule = polymer)
What are macromolecules?
- proteins
- DNA/RNA (nucleic acids)
- complex carbohydrates (polysaccharides)
- lipids (non-polymeric biomolecule)
What is a biomolecule?
Any type of molecule produced by a living organism
What are the 4 levels of carbohydrates?
- Monosaccharides (simple = sugars)
- Disaccharides (simple = sugars)
- Oligosaccarides (complex carbs)
- Polysaccharides (complex carbs)
What are the types of monosaccharides? (Single unit building block of carbohydrates)
Hexose: (building block higher order carbs) - glucose - fructose - galactose Pentose: (part of larger molecules) - deoxyribose (part of DNA nucleotide) - ribose (part of RNA nucleotide)
What makes up a disaccharide?
Two monosaccharides
What are the types of disaccharides?
- glucose + fructose = sucrose
- galactose + glucose = lactose
- glucose + glucose = maltose
What is a feature of hexose monosaccharides?
They are the 3 most common building blocks in the body
What is the only difference between the two pentose monosaccharides?
One for RNA and one for DNA
What are oligodaccharides made up of?
3-10 monosaccharides
What are polysaccharides made up of?
More than 10 monosaccharides
What are the 3 different types of polysaccharides?
- starch
- glycogen
- cellulose
What are the two types of starch?
- amylose
- amylopectin
Is starch a plant or animal carbohydrate?
Plant
What is starch made up of?
Glucose monomers linked with an (alpha) 1-4 glycosidic bond
Can the glycosidic bonds in starch molecules be easily broken? How and why?
Yes by enzymes the release glucose for energy
Is glycogen an animal or plant carbohydrate?
Animal
What is glycogen made up of?
Glucose monomers linked with alpha 1-4 glycosidic bonds
Can the glycosidic bonds in glycogen be broken easily? How and why?
Yes by enzymes to release glucose for energy
Is cellulose a plant or animal carbohydrate?
Plant
What is cellulose made up of?
Glucose monomers linked with a beta 1-4 glycosidic bond
Can the glycosidic bonds in cellulose be broken down easily?
No enzymes can’t break the bonds for energy
What forms can the glucose monomers be in?
Linear or ring
What are the two different glucose monomer ring structures?
- alpha (OH group only down)
- beta (OH group only up)
Are there more than one linear structures of glucose monomers?
No
What are the functions of carbohydrates?
- cell recognition
- storage of glucose (alpha - starch plant, glycogen animal)
- structure (cellulose plants)
Are lipids polymers?
No
How do lipids and water behave together
They do not mix (oil)
- lipids are hydrophobic
What are the 3 functions of lipids?
- structural
- regulatory (testosterone/oestrogen)
- energy
What are the two nucleic acids?
- DNA (deoxyribonucleic acid)
- RNA (ribonucleic acid)
What do nucleotides form?
Nucleic acids (polymers)
What are proteins?
Molecules by which cells perform their functions in the whole organism
What is the process from DNA to a protein?
A gene in DNA transcribes to a mRNA
- which transcribes to a protein
How many different amino acids are there? How are they different?
20 different
Differ by the R group (side chain)
How many protein coding genes are in the body?
22,000
How many unique proteins are there in the human body?
100,000
Genes give rise to proteins, one or many?
One or many proteins
What are some functions of proteins?
- structural
- regulatory
- contractile
- transport
Why does the plasma membrane have a selective barrier?
- oxygen
- nutrients
- waste
What is the structure of the plasma membrane?
Double layer phospholipids
What about the plasma membrane restricts the size a cell can be?
The surface area because only so many reactions can occur by things transporting through the membrane
What is the cytoplasm?
Everything inside the plasma membrane (cytosol and organelles)
Excluding the nucleus
What is the cytosol?
Gel fluid
Contains ions/water/proteins
What is the cytoplasm doing constantly?
Moving
What is the approximate pH of the cytoplasm?
7
What are ribosomes made of?
Ribosomal RNA and protein (not organelles surrounded by membrane)
What do the ribosomes do?
Carry out protein synthesis
Where are the ribosomes free?
In the cytosol
Where are the ribosomes bound?
Outside of ER or nuclear envelope