Topic 3

Created by

Bicepking

Cards (100)

Description of nucleus 
Large organelle surrounded by a nuclear envelope which contains pores. the nucleus contains chromatin (which is made from DNA and proteins and a structure called the nucleolus.
What is the function of nucleus ? 
Controls the cells activities by controlling the transcription of DNA. DNA contains instructions to make proteins. Pores allow substances to move between the nucleus and cytoplasm. The nucleolus makes ribosomes
Description of lysosome 
A round organelle surrounded by a membrane with no clear internal structure
What is the function of the lysozyme? 
Contains digestive enzymes which are used to digest invading cells or break down worn components of the cell
Describe a ribosome 
A very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum. It is made up of proteins and RNA. No membrane
What is the function of a ribosome? 
Function of ribosome ?Site where proteins are synthesised
Describe the RER 
A system of membrane bound flattened sacs. the surface is covered with ribosomes
What is the function of the RER?
Folds and processes proteins that have been made at the ribosomes
Describe the SER 
Description of smooth endoplasmic reticulum ?a system of membrane bound flattened sacs but with no ribosomes
What is the function of the SER?
Function of smooth endoplasmic reticulum ?synthesises and processes lipids
Describe the Golgi apparatus 
A group of fluid filled membrane bound flattened sacs. formed by the fusion of vesicles from the ER
What is the function of the Golgi apparatus?
It processes and packages new lipids and proteins. it also makes lysosomes
Describe the mitochondria 
Description of mitochondria ?Double membrane- inner one is folded to form a structure called cristae. inside is the matrix which contains enzymes involved in respiration
What is the function of the mitochondria?
Function of mitochondria ?site of aerobic respiration, where ATP is produced. found in large numbers in cells that are very active and require a lot of energy.
Describe the centriole 
small hollow cylinders made of microtubules. found in animal cells but only some plant cells
What is the function of the centriole?
Involved with the separation of chromosomes during cell division
What type of proteins do ribosomes make?
Ribosomes on the rER make proteins that are excreted or attached to the cell membrane. Free ribosomes in the cytoplasm make proteins that stay in the cytoplasm.
What happens once the new proteins are made ?
They enter into the rER and are folded and processed. Then they are transported to the Golgi apparatus in vesicles. The vesicles fuse to form the flattened sacs of the Golgi and the Golgi further processes the proteins. The proteins enter more vesicles and are transported around the cell
What is found in the cytoplasm in prokaryotic cells?
No membrane bound organelles and has smaller ribosomes than in eukaryotic cell
What is the flagellum?
long hair like structure that rotates to make the prokaryotic cell move. not all prokaryotes have a flagellum and some have more than one
What is circular DNA?
Long coiled up strand of DNA that is not attached to any histone proteins
What is a plasmid? 
Small loops of DNA that aren't part of the main circular DNA molecule. contain genes for things like antibiotic resistance
What is a mesosome?
inward folds in the plasma membrane (thought to be artifacts of cell staining and preparation)
What is a capsule?
Made up of secreted slime. helps protect bacteria from attack by cells of the immune system and prevents dehydration
What is the Pilli? 
Short hair like structure. helps prokaryotes stick to other cells and can be used to transfer genetic material between cells
What is the cell wall in prokaryotes made of?
Support the cell and prevents it from changing shape. made of murein glycoprotein or peptidoglycan
What is the function of the plasma membrane?
Mainly made of lipids and proteins. controls the movement of substances into and out of the cell
What kind of cell does mitosis produce ?
genetically identical daughter cells
What is mitosis needed for ?
growth, repairing damaged tissues and for asexual reproduction
What does the cell cycle consist of ?
Interphase which is a period of cell growth and DNA replication (G1, S and G2) then Mitosis
What happens during Interphase?
Gap phase 1 - cell grows and new organelles and proteins are made. Gap phase 2 - cell keeps growing and proteins needed for cell division are made. ATP content is increased. Synthesis - cell replicates its DNA ready to divide by mitosis
Order of stages in mitosis
prophase, metaphase, anaphase and telophase
What happens in prophase?
Chromosomes condense, becoming shorter and thicker, each chromosome is visible as 2 strands called chromatids. centrioles start moving to opposite ends of the cell, forming a network of protein fibers called a spindle. nuclear envelope breaks down and the chromosomes lie free in the cytoplasm
What happens in metaphase? 
Metaphase ?chromosomes, each with 2 chromatids line up along the middle of the cell and become attached to the spindle fibers at their equator by their centromeres.
What happens in anaphase?
Anaphase ?centromeres divide, separating each pair of sister chromatids. the spindles contract, pulling chromatids to opposite poles of the spindle, centromere first
What happens in telophase?
Telophase ?chromatids reach the opposite poles on the spindle. they uncoil and become long and thin and are called chromosomes again. a nuclear envelope forms around each group of chromosomes so there are 2 nuclei. The cytoplasm divides and there are now 2 genetically identical daughter cells.
How does mitosis ensure genetic consistency ?
DNA replication before mitosis. The arrangement of chromosomes on the spindle and the separation of chromosomes to the pole
What is a tissue?
Group of similar cells that are specially adapted to work together to carry out a particular function
What is an organ?
Group of different tissues that work together to perform a particular function
What is an organ system? 
Group of organs that work together to perform a particular function