Unit 1 AOS 1 Flashcards
Exergonic reactions
Releases energy
Anabolic reactions
Building up of complex organic molecules from simpler substances
Endergonic reactions
Uses energy from internal catabolic reactions or an external energy source such as sunlight
Metabolism
All the chemical processes or reactions that take place in an organism
Vitamins
Are a group of organic compounds that occur in small quantities of food.
They are essential for many chemical reactions in cells.
Minerals
Are inorganic ions required by both animals and plant cells.
Minerals play a role metabolic processes and are incorporated into many structures produced by cells.
Hydrophilic substances
Substances that dissolve in water
Hydrophobic substances
Are substances that tend to be insoluble in water
What are the three elements found in all organic compounds?
Hydrogen
Oxygen
Carbon
Catabolic reactions
Breaking down of complex organic compounds to simpler substances
Diffusion
The gradual movement of particles from places where there are lots of them (high concentration) to places where there are less of them (low concentration)
Osmosis
Is the diffusion of water molecules across a partially permeable membrane
Isotonic
Refers to a solution having the same concentration of dissolved substances as the solution to which it is compared (isotonic is normal)
Hypotonic
Refers to a solution having lower concentration of dissolved substances than the solution to which it is compared
Hypertonic
Refers to a solution having higher concentration of dissolved substances than the solution to which it is compared
Turgid
State of a cell that is firm because of water uptake
Plasmolysed
The shrinking of protoplasm away from the cell wall due to water loss from osmosis, thereby resulting in gaps between the cell wall
Flaccid
A state of limpness of a cell because of water loss
Lyse
To induce lysis, or to cause dissolution or destruction of a cell membrane with lysin.
Facilitated diffusion
Passive transport of polar molecule in/out of cell via transport proteins found in plasma membrane.
No energy is used
Passive transport
Transport of molecules across the plasma membrane that does NOT require energy.
Molecules move down their concentration gradient (from high concentration to low concentration)
Active transport
Transport of molecules in/out of cells via transport proteins in the plasma membrane. REQUIRES ENERGY.
Molecules move against there concentration gradient (low concentration to high concentration)
Exocytosis
Bulk transport of large molecules or particles OUT of the cell. REQUIRES ENERGY.
E.G. A vesicle may fuse with the membrane and expel its contents
Endocytosis
Bulk transport of large molecules or particles INTO the cell. REQUIRES ENERGY.
E.G. the membrane will fold inward, trapping material from the outside
Pinocytosis
Endocytosis of FLUIDS into cells
Phagocytosis
Endocytosis of SOLIDS into cells
Photosynthesis
Is the conversion of light energy into chemical energy
Cellular respiration
Process of converting chemical energy of food into a form usable by cells, typically ATP
Mitosis
Process of nuclear division in which the replicated genetic material in the nucleus are separated and two nuclei are formed
Cytokinesis
Division of cytoplasm and involves the separation of cytosol and the organelles
Volume formula
Length x Width x Height
Surface area formula
Area (Length x Width) x Number of sides
Rate of Surface area to volume ratio factors
The rate of exchange of substances depends on the organisms surface area in contact with the surroundings
The requirements for materials depends on the volume, so the ability to meet the requirements depends on the SA:V ratio
The smaller the SA= faster diffusion rate
How do large organisms survive (based on diffusion and size factors)
The large organisms survive as they are multicellular. Having lots of small cells instead of one big cell allows for a faster diffusion rate
General role of enzymes
They are vital for chemical reactions
They generally speed up the reactions and act as biological catalysts
Enzymes bind to specific molecules called substrate/s in a particular region called an active site.
Carbohydrates monomer/polymer
Monomer: glucose
Polymer: starch, cellulose, glycogen
Protein monomer/polymer
Monomer: amino acid
Polymer: polypeptide
Different lipids
=fats, waxes or oils
Subunits: glycerol and fatty acids
E.g. Triglycerides, phospholipids
Nucleic acid: deoxyribonucleic acid (DNA): where are they found/ monomer and polymer
-mainly located in chromosomes
-also found in chromatin, plasmids, chloroplasts, mitochondria
Monomer: Nucleotide
Polymer: DNA
What does DNA consist of?
Deoxyribose sugar
Phosphate part
Nitrogen containing base
4 nitrogenous containing bases for DNA and pairs
Adenine, thymine, cytosine, guanine
Base pairs: A-T and C-G
Ribonucleic acid (RNA) monomer/ polymer
Monomer: nucleotide
Polymer: RNA
What does RNA consist of?
Ribose sugar
Phosphate part
Nitrogen containing base
What are the nitrogenous bases for RNA
Adenine, Uracil, Guanine, cytosine
What are the three types of RNA and their functions
Ribosomal RNA (rRNA): together with proteins, make ribosomes
Messenger RNA (mRNA): carries genetic message to ribosomes where the message is translated into a protein
Transfer RNA (tRNA): carry amino acids to ribosomes where they construct proteins
Stages of mitosis IPMAT
Interphase Prophase Metaphase Anaphase Telophase
Interphase
The nucleus is well defined and chromosomes are not visible. (It is during this phase that the nuclear DNA replicates)
Prophase
Double-stranded chromosomes held together at centromere become progressively more condensed and the nuclear membrane gradually disappears
Metaphase
The spindle forms in the cell and the fully condensed double-stranded chromosomes line up around the equator of the spindle
Anaphase
The centromere of each chromosome divides so that the single-stranded chromosomes of the pair migrate to opposite poles of the spindle
Telophase
A nuclear membrane forms around each of the two groups of separated chromosomes, and the chromosome progressively becomes less condensed
Structure of cell membrane
Two layers of phospholipids which are the main structural components of membranes
Function of cell membrane
Phospholipid bilayer prevents passage of most polar and I’ll charged molecules. E.g. Impermeable to carbohydrates and ions
Small molecules can easily pass through pores/gaps by diffusion
Some proteins transport substances across the membrane-called transport/carrier proteins. Molecules transported include those that are not soluble in lipids or are too large to fit through pores/gaps in the bilayer
