Cell Biology Flashcards
Nucleus
-Contains chromosomes
- Chromosomes contain DNA which tells cells how to function
Nucleolus
-Made up of RNA
-Produces ribosomes
cell membrane
-Covered in carbohydrates to help recognise other cells
-Composed of a phospholipid bilayer
-Allows certain substances to move in an out (selectivley permeable)
Simple Diffusion
Oxygen and water enter the cell this way.
Facilitated diffusion
Substance attatches to a carrier protien to help it cross the membrane.
This occurs through pores in the cell membrane
Active Transport
-Low to high concentration
-Needs ATP
Passive transport
-High to low concentration
-no ATP
Endocytosis
Engulfed in mebrane
Exocytosis
particles are expelled from the cell
Cytoplasm
-Provides the cell with support
-Contains organelles, glucose, protiens and ions
Mitochondria
-Cellular respiration
-Extraction of energy from food
Lysosomes
-Digest material taken in by cell
-Destroy worn out cells
Ribosomes
-Protien Synthesis
-Binds to mRNA
Rough Endoplasmic Reticulum
- Transports and adds structure to proteins
Golgi Body
-modification of protiens for their final destination
-helps formations of lysosomes
Smooth Endoplasmic Reticulum
-Synthesis and transport of lipids and steroids
Peroxisomes
Active process of detoxification
Vacuoles
- Maintains pressure within a plant cell
Flagella
An extension of the cell membrane on certain cells to allow propelling moving (e.g. spermatoza)
Cillia
Allow smaller movements over the cell surface to move debris
Somatic cells
-Divide by mitosis
-Contain diploid number of chromosomes
-Almost all cells are somatic cells
Germ Cells
-Divide by meiosis
-sex cells
-Haploid number of chromosomes
Mitosis
Prophase
-Chromosomes replicated
-Nuclear membrane breaks down
-Chromosomes contract and shorten
-Spindle fibres start to form
Mitosis:
Metaphase
- Chromosomes line up on equator and draw apart
Mitosis
Anaphase
-Chromosomes attach to spindle fibres
-Chromatids move apart
Mitosis:
Telophase
-Chromatids will be new chromosomes
-Spidle fibres break down
-Nuclear membrane reforms itself
Interphase
DNA makes a copy of itself ready for prophase
Meiosis:
Prophase 1
-Crossing over occurs here resulting in new combinations of genes
Meiosis:
Metaphase 1
-Chromosomes arrange in pairs
Meiosis:
Anaphase 1
Pairs seperate into chromatids and migrate along spindle fibres
Meiosis:
Telophase 1
-Cytoplasm divides
-2 daughter cells are formed
Haploid
half the full set of chromosomes - found in sex cells only
Diploid
full number of chromosomes
Chromatid
half a chromosome
