biology: the cell and its organelles

Question 1

cell theory

Answer 1

1. a cell is the basic structural, functional, and biological unit of organisms
2. a cell is the smallest unit of life
3. all cells come from pre-existing cells
4. all organisms are made of one or more cells

Question 2

advantage of multicellularity

Answer 2

1. increased SA for diffusion
2. longer lifespan
3. specialization of cells into cell types, tissues and organs
4. protection, feeding, locomotion, reproduction

Question 3

nucleus

Answer 3

contains genetic material as chromosomes
surrounded by nuclear envelope (double membrane supported by nuclear lamina)

chromatin: DNA and histone proteins that make up chromosomes in eukaryotes
in human: 46 chromosomes

Question 4

nucleolus

Answer 4

in nucleus
contains rRNA
site of RNA synthesis
ribosomes use mRNA to synthesize proteins in the cytoplasm

Question 5

rough ER

Answer 5

ribosome studded
PROTEIN synthesis
membrane proteins are inverted during translation into the ER membrane before they are sent to various parts of the cell

Question 6

smooth ER

Answer 6

no ribosomes
LIPID synthesis
detoxification
calcium storage

Question 7

golgi apparatus

Answer 7

trafficking center
manufactures, recieves, sorts, modifies, ships many molecules

VESICLES ARRIVE FROM ER, FUSE WITH GA MEMBRANES AND LEAVE GA IN CIS-TRANS DIRECTION

where proteins can mature (posttranslational modifications) (after protein synthesis)
- phosphorylation, glycosylation or acetylation

Question 8

lysosome

Answer 8

digestive organelle
contains hydrolytic enzymes, is very acidic, work at low pH
fusion of lysosomes with phagocytosis vesicles allow digestion of preys into cytosol
DERIVE FROM GA

Question 9

perioxisome

Answer 9

single membrane oxidative organelle
contains enzymes that remove hydrogen atoms from substrates and transfer them to oxygen
- producing hydrogen peroxide

break down fatty acids for cell respiration
detoxification

Question 10

vacuole

Answer 10

large vesicles derived from ER and GA
semi-permeable membrane

storage of nutritious molecules, poisonous molecules, lytic enzymes, pigments, water and ions
cell growth, structural support and tendrils
can produce/ store molecules

Question 11

how do photosynthesis and cell respiration work together

Answer 11

photosynthesis in the chloroplast uses light energy, CO2 and H2O to produce glucose and O2

cell respiration in the mitochondria uses this glucose and O2 to produce useable CO2, H2O, and energy (ATP)